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Evolutionary psychiatry, also known as Darwinian Psychiatry, is a theoretical approach to
psychiatry Psychiatry is the medical specialty devoted to the diagnosis, treatment, and prevention of deleterious mental disorder, mental conditions. These include matters related to cognition, perceptions, Mood (psychology), mood, emotion, and behavior. ...
that aims to explain
psychiatric disorder A mental disorder, also referred to as a mental illness, a mental health condition, or a psychiatric disability, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. A mental disorder is ...
s in
evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
ary terms. As a branch of the field of
evolutionary medicine Evolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. Modern biomedical research and practice have focused on the molecular and physiological mechanisms underlying hea ...
, it is distinct from the medical practice of psychiatry in its emphasis on providing
scientific Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...
explanations rather than treatments for mental disorder. This often concerns questions of ultimate causation. For example,
psychiatric genetics Psychiatric genetics is a subfield of behavioral neurogenetics and Behavioural genetics, behavioral genetics which studies the role of genetics in the development of mental disorders (such as alcoholism, schizophrenia, bipolar disorder, and autism) ...
may discover genes associated with mental disorders, but evolutionary psychiatry asks why those genes persist in the population. Other core questions in evolutionary psychiatry are why heritable mental disorders are so common how to distinguish mental function and dysfunction, and whether certain forms of suffering conveyed an adaptive advantage. Disorders commonly considered are depression,
anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
,
schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
,
autism Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing d ...
,
eating disorder An eating disorder is a mental disorder defined by abnormal eating behaviors that adversely affect a person's health, physical or mental health, mental health. These behaviors may include eating too much food or too little food. Types of eatin ...
s, and others. Key explanatory concepts are of
evolutionary mismatch Evolutionary mismatch (also "mismatch theory" or "evolutionary trap") is the evolutionary biology concept that a previously advantageous phenotypic trait, trait may become maladaptation, maladaptive due to change in the biophysical environment, e ...
(when modern environments cause mental health conditions) and the fact that evolution is guided by
reproductive success Reproductive success is an individual's production of offspring per breeding event or lifetime. This is not limited by the number of offspring produced by one individual, but also the reproductive success of these offspring themselves. Reproduct ...
rather than
health Health has a variety of definitions, which have been used for different purposes over time. In general, it refers to physical and emotional well-being, especially that associated with normal functioning of the human body, absent of disease, p ...
or wellbeing. Rather than providing an alternative account of the cause of mental disorder, evolutionary psychiatry seeks to integrate findings from traditional schools of psychology and psychiatry such as
social psychology Social psychology is the methodical study of how thoughts, feelings, and behaviors are influenced by the actual, imagined, or implied presence of others. Although studying many of the same substantive topics as its counterpart in the field ...
,
behaviourism Behaviorism is a systematic approach to understand the behavior of humans and other animals. It assumes that behavior is either a reflex elicited by the pairing of certain antecedent stimuli in the environment, or a consequence of that indivi ...
,
biological psychiatry Biological psychiatry or biopsychiatry is an approach to psychiatry that aims to understand mental disorder in terms of the biology, biological function of the nervous system. It is interdisciplinary in its approach and draws on sciences such as ...
and
psychoanalysis PsychoanalysisFrom Greek language, Greek: and is a set of theories and techniques of research to discover unconscious mind, unconscious processes and their influence on conscious mind, conscious thought, emotion and behaviour. Based on The Inte ...
into a holistic account related to evolutionary biology. In this sense, it aims to meet the criteria of a Kuhnian
paradigm shift A paradigm shift is a fundamental change in the basic concepts and experimental practices of a scientific discipline. It is a concept in the philosophy of science that was introduced and brought into the common lexicon by the American physicist a ...
. Though heavily influenced by
evolutionary psychology Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regard to the ancestral problems they evolved ...
, as Abed and St John-Smith noted in 2016, "Unlike evolutionary psychology, which is a vibrant and thriving sub-discipline of academic psychology with a strong and well-funded research program, evolutionary psychiatry remains the interest of a small number of psychiatrists who are thinly scattered across the world." It has gained increasing institutional recognition in recent years, including the formation of an evolutionary psychiatry special interest group within the
Royal College of Psychiatrists The Royal College of Psychiatrists is the main professional organisation of psychiatrists in the United Kingdom, and is responsible for representing psychiatrists, for psychiatric research and for providing public information about mental healt ...
and the Section on Evolutionary Psychiatry within the
World Psychiatric Association The World Psychiatric Association (WPA) is an international Umbrella organization, umbrella organisation of psychiatric societies. Objectives and goals Originally created to produce world psychiatric congresses, it has evolved to hold regional ...
, and has gained traction with the publication of texts aimed at the popular audience such as ''Good Reasons for Bad Feelings: Insight from the Frontier of Evolutionary Psychiatry'' by Randolph Nesse.


History

The pursuit of evolutionary psychiatry in its modern form can be traced to the late 20th century. A landmark text was George Williams and Randolph Nesse's ''Why We Get Sick: The New Science of Darwinian Medicine'' (which could also be considered as marking the beginning of evolutionary medicine), the publication of ''Evolutionary Psychiatry: A New Beginning'' by John Price and Anthony Stevens and others. However, the questions which evolutionary psychiatry concerns itself with have a longer history, for instance being recognised by
Julian Huxley Sir Julian Sorell Huxley (22 June 1887 – 14 February 1975) was an English evolutionary biologist, eugenicist and Internationalism (politics), internationalist. He was a proponent of natural selection, and a leading figure in the mid-twentiet ...
and
Ernst Mayr Ernst Walter Mayr ( ; ; 5 July 1904 – 3 February 2005) was a German-American evolutionary biologist. He was also a renowned Taxonomy (biology), taxonomist, tropical explorer, ornithologist, Philosophy of biology, philosopher of biology, and ...
in an early paper considering possible evolutionary explanations for what has become known as the 'schizophrenia paradox'. Concepts applied by modern evolutionary psychiatry to explain mental disorder are also much older than the field, in many cases. Psychological suffering as an inevitable, and sometimes useful, part of human existence has been long-recognised, and the idea of
divine madness Divine madness, also known as ''theia mania'' and crazy wisdom, is unconventional, outrageous, unexpected, or unpredictable behavior linked to religious or spiritual pursuits. Examples of divine madness can be found in Buddhism, Christianity, He ...
pervades ancient societies and religions.
Cesare Lombroso Cesare Lombroso ( , ; ; born Ezechia Marco Lombroso; 6 November 1835 – 19 October 1909) was an Italian eugenicist, criminologist, phrenologist, physician, and founder of the Italian school of criminology. He is considered the founder of m ...
, a pioneering psychiatrist, began utilising evolutionary theory to explain mental disorder as early as 1864, proposing that insanity was the price of genius, as human brains had not evolved with the capacity to become hyper-intelligent and creative and yet remain sane. Darwin applied evolutionary theory to explain psychological traits and emotions, and recognised the usefulness of studying mental disorders in pursuit of understanding natural psychological function. Freud was heavily influenced by Darwinian theory, and towards the end of his life recommended psychoanalysts should study evolutionary theory. Bowlby's attachment theory was developed in explicit reference to evolutionary theory. In 2016 the Evolutionary Psychiatry Special Interest Group (EPSIG) was set up in the
Royal College of Psychiatrists The Royal College of Psychiatrists is the main professional organisation of psychiatrists in the United Kingdom, and is responsible for representing psychiatrists, for psychiatric research and for providing public information about mental healt ...
, UK by Riadh Abed and Paul St-John Smith. It is now the largest global institution for connecting psychiatrists and researchers interested in evolutionary psychiatry with over 1700 members. It has run several seminars and meetings dedicated to evolutionary psychiatry, hosting lectures by prominent academics such as
Simon Baron-Cohen Sir Simon Philip Baron-Cohen (born 15 August 1958) is a British clinical psychologist and professor of developmental psychopathology at the University of Cambridge. He is the director of the university's Autism Research Centre and a Fellow of ...
and
Robin Dunbar Robin Ian MacDonald Dunbar (born 28 June 1947) is a British biological anthropologist, evolutionary psychologist, and specialist in primate behaviour. Dunbar is professor emeritus of evolutionary psychology of the Social and Evolutionary Neuros ...
. All of the meetings are available on the EPSIGUK YouTube channel. EPSIG also publishes regular newsletters, organising conferences, conducting interviews and hosting special essays related to evolutionary psychiatry (for which there is not yet a dedicated academic journal). As Riadh Abed, (previous chair) stated in a newsletter "Our aims are both big and radical: they are for evolution to be accepted as the overarching framework for psychiatry and for evolution to take center stage in our understanding of mental health and mental disorder." Abed and St-John Smith edited a 2022 volume ''Evolutionary Psychiatry: Current Perspectives on Evolution and Mental Health'', co-published by the Royal College of Psychiatrists and Cambridge University Press, marking the most extensive publication in the field to date, and forming the basis for the first podcast dedicated to evolutionary psychiatry, th
'Evolving Psychiatry'
podcast.


Psychological function and dysfunction

Mental disorders are often defined by 'dysfunction' in psychiatric manuals such as the DSM, without a precise definition of what constitutes dysfunction, allowing any mental state deemed socially unacceptable (such as
homosexuality Homosexuality is romantic attraction, sexual attraction, or Human sexual activity, sexual behavior between people of the same sex or gender. As a sexual orientation, homosexuality is "an enduring pattern of emotional, romantic, and/or sexu ...
) to be considered dysfunctional, and thus a mental disorder. Evolutionary theory is uniquely placed to be able to distinguish biological function from dysfunction by evolutionary processes. Unlike the objects and processes of
physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...
and
chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
, which cannot strictly be said to be functioning nor dysfunctioning, biological systems are the products of evolution by
natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...
, and so their 'function' and 'dysfunction' can be related to that evolutionary process. The concept of evolutionary function is tied to the reproductive success brought about by phenotypes which caused genes to be propagated. Eyes evolved to see – the function of the eyes is to see – so dysfunctional eyes are those that cannot see. This sense of function is defined by the evolutionary history of eyesight providing reproductive success, not current cultural opinions of normality and abnormality on which common conceptions of health and disorder often depend. Jerome Wakefield's influential 'Harmful Dysfunction' definition of disorder utilises evolutionarily selected effects to ground the concept of 'dysfunction' in the objective process of evolution. Wakefield proposes that mental disorder must be both harmful, in a value-defined sense, and dysfunctional, in an evolutionary sense. This grounding of dysfunction in an objective historical process is important in the context of psychiatry's history of labelling socially undesirable mental states and traits as 'disorders', such as female masturbation and homosexuality. Current diagnostic manuals are decided by consensus. For example, in 1973 the APA called a vote to reconsider homosexuality's status as a mental disorder. By a 58% majority, it was struck off. The category of
borderline personality disorder Borderline personality disorder (BPD) is a personality disorder characterized by a pervasive, long-term pattern of significant interpersonal relationship instability, an acute fear of Abandonment (emotional), abandonment, and intense emotiona ...
was created upon the basis of a single paper and consensus between about a dozen psychiatrists. In 2014 psychiatrists voted on the features of a new disorder, internet gaming disorder. The reliance on votes and expert consensus rather than objective evidence or
biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...
s is a longstanding criticism of psychiatry that evolutionary psychiatry can avoid by adopting the evolutionary definition of dysfunction.


Evolutionary causation and Tinbergen's four questions

The research questions and concerns of
evolutionary medicine Evolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. Modern biomedical research and practice have focused on the molecular and physiological mechanisms underlying hea ...
and psychiatry can be distinguished from normal
biomedicine Biomedicine (also referred to as Western medicine, mainstream medicine or conventional medicine)
and biological-psychiatry research as asking ultimate instead of proximate questions. This ultimate-proximate distinction was introduced by
Ernst Mayr Ernst Walter Mayr ( ; ; 5 July 1904 – 3 February 2005) was a German-American evolutionary biologist. He was also a renowned Taxonomy (biology), taxonomist, tropical explorer, ornithologist, Philosophy of biology, philosopher of biology, and ...
to identify different levels of causational explanation: proximate explanations refer to mechanistic biological processes (e.g. genes, ontogenetic development, hormones, neurological structure and function) whilst ultimate explanations ask about the evolutionary process of natural selection which led to these biological structures and processes functioning as observed. This could be conceived of as proximate explanations are 'how' questions whilst ultimate explanations are 'why' questions.
Niko Tinbergen Nikolaas "Niko" Tinbergen ( , ; 15 April 1907 – 21 December 1988) was a Dutch biologist and ornithologist who shared the 1973 Nobel Prize in Physiology or Medicine with Karl von Frisch and Konrad Lorenz for their discoveries concerning th ...
further deconstructed this ultimate-proximate distinction into his 'four questions'. These questions of mechanism, ontogeny, function and phylogeny can be asked of any single trait or disorder (often behavioural, although not necessarily) to identify the different questions of causation which are simultaneously relevant. Proximate questions can be separated into questions of mechanism, which concerns how the trait works, the structure and process of its biological mechanism, and questions of
ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the ovum, egg to adult. The term can also be used to refer to t ...
or individual development which concerns how the trait develops in an individual. Ultimate questions can be either of or evolutionary function or adaptive value, which concerns how the trait influenced fitness throughout evolutionary history; and questions of
phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...
or evolution, which concern the history of a trait down the phylogenetic tree. To take the example of depression, we can ask about proximate mechanisms (e.g. neurotransmitter properties), ontogenetic development (e.g. neurological development over an individual's lifespan), adaptive function (e.g. low mood system) and phylogeny (e.g. apparent low mood in reaction to social defeat in primates).


Key explanatory concepts in evolutionary psychiatry

Mental disorder results from many different environmental and genetic causes, with various complex neurological correlates – but
evolutionary medicine Evolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. Modern biomedical research and practice have focused on the molecular and physiological mechanisms underlying hea ...
recognises several general principles which allow vulnerability to disorder. Adapted from Nesse (2019), Stearns (2016) and Gluckman (2016).


Reproductive success over health

Natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...
acts on
reproductive fitness Fitness (often denoted w or ω in population genetics models) is a quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals ...
, not biological states which are what may be considered healthy; healthy states are only selected if they also have positive effects on reproductive success. This is used in
evolutionary medicine Evolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. Modern biomedical research and practice have focused on the molecular and physiological mechanisms underlying hea ...
to explain aging and diseases of senescence: diseases which appear past reproductive age have minimal effect on fecundity. Psychological suffering and various cognitive states which may seem unhealthy or disorderly may equally be products of evolutionary processes if they increased reproductive success. Evidence of this may be seen in disorders associated with substantial apparent dysfunction, yet average levels of fertility.


Mismatch

Evolutionary mismatch Evolutionary mismatch (also "mismatch theory" or "evolutionary trap") is the evolutionary biology concept that a previously advantageous phenotypic trait, trait may become maladaptation, maladaptive due to change in the biophysical environment, e ...
occurs when evolved traits become maladaptive due to changes in the environment. This is a common factor causing evolutionary change (e.g. in the peppered moth) and is relevant to medicine when the mismatched traits cause problems affecting health. Psychiatric conditions may in some cases be evolved states which we are misinterpreting as disorders because they no longer fit our social expectations; or they may be mental states or traits which would manifest healthily in ancestral environments, but become pathological due to some feature of modern environments. Evidence of mismatch is most prominent when comparing traditional-living humans to modern-living humans or when new environmental factors arise which clearly cause disease (e.g. the availability of cheap, high calorie foods causing obesity).


Defences

Psychological responses such as fear and panic are adaptive in many situations, especially of imminent danger, and seen in multiple species. Certain mental disorders may result from such responses, either as a maladaptive overactivation of the response, or as an adaptive process which is specifically tuned to over-activate because the fitness cost of the response is outweighed by the fitness benefit – called the smoke detector principle. The fact that such experiences are highly distressing, debilitating and inappropriate leads to their diagnosis as mental disorders.


Mutation-selection balance

Natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...
acts upon
genetic mutations In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...
, which are present in every generation, removing those which reduce fitness and increasing the prevalence of those which improve fitness. Mutations are also more likely to reduce fitness than improve it. Biological traits with a large mutational target size, such as brains, where over 80% of the genome is expressed, are especially likely to be suspect to harmful mutations which negatively affect cognitive function, which are then removed by natural selection. Such mutations are often associated with intellectual disability, certain cases of
autism Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing d ...
,
schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
, and many more disorders. The fact that de-novo mutations cause such disorders in a few cases has been used to argue that the other cases are caused by as-yet undiscovered disease processes, although the presence of
heterogeneity Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, i ...
within disorder categories and the lack of discovered
pathology Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...
despite significant work in
neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...
and
genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...
is evidence against that view.


Evolutionary explanations for specific disorders


Schizophrenia

Schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
is primarily characterized by
psychosis In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or inco ...
(
hallucination A hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming ( REM sleep), which does not involve wakefulness; pse ...
s and
delusion A delusion is a fixed belief that is not amenable to change in light of conflicting evidence. As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, hallucination, or some other m ...
s) and symptoms of cognitive debilitation such as erratic speech, lost interest in normal activities and disordered thinking. It is the most extreme condition of the schizophrenia or psychosis spectrum, which includes
schizotypy In psychology, schizotypy is a theoretical concept that posits a continuum (theory), continuum of personality psychology, personality characteristics and experiences, ranging from normal dissociative, imaginative states to extreme states of mind ...
and other psychotic disorders, arguably extending to unusual experiences such as perceiving ghosts or believing in magic which are common in the population. Schizophrenia is a heritable condition, prevalent in slightly less than 1% of the population, with negative effects of fecundity, especially in men. Because of this, it was perhaps the first psychiatric condition explicitly raised as specifically requiring an evolutionary explanation, in the so-called 'schizophrenia paradox' (now more generally known as the paradox of common, harmful, heritable mental disorders). To explain schizophrenia's persistence various evolutionary hypotheses have been made. Hypotheses of schizophrenia as a true dysfunction are plentiful. It has been hypothesised that schizophrenia is a dysfunctional byproduct of human evolution for language and brain hemisphere lateralization, or a dysfunction of the social brain, or related to theory-of-mind. Other theories have referred to the possibility it is caused by mutation-selection balance. However, the expected rare and ''de novo'' mutations have only been found in a small proportion of cases. Many alleles predisposing to schizophrenia are common in the population, making adaptive hypotheses plausible, as has been noted since the mid 20th century. Hypotheses explaining schizophrenia as resulting from adaptation vary widely. Early theorists proposed it conveyed improvements to the
immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...
or illness recovery or facilitates group-splitting. Inspired by the longstanding cultural ideas of madness as related to
genius Genius is a characteristic of original and exceptional insight in the performance of some art or endeavor that surpasses expectations, sets new standards for the future, establishes better methods of operation, or remains outside the capabiliti ...
,
Nettle Nettle refers to plants with stinging hairs, particularly those of the genus '' Urtica''. It can also refer to plants which resemble ''Urtica'' species in appearance but do not have stinging hairs. Plants called "nettle" include: * ball nettle ...
proposed that schizotypy could be related to creative success, which added to mating success, and that the positive effects of schizotypal traits might be an explanation for why these traits persist. However, the measured fecundity benefit of such traits has been found to not outweigh the cost of schizophrenia via inclusive fitness (although this may be due to
selection bias Selection bias is the bias introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population inte ...
). The shamanism hypothesis of schizophrenia states that in traditional societies the experience of psychosis facilitated the induction of
shamans Shamanism is a spiritual practice that involves a practitioner (shaman) interacting with the Spirit (supernatural entity), spirit world through Altered state of consciousness, altered states of consciousness, such as trance. The goal of th ...
( magico-religious practitioners such as medicine men, diviners, witch doctors, exorcists and mediums). Shamanism is a common feature of human societies, with certain individuals deemed to have a particular connection to the supernatural world which gives them the ability to perform magic, especially healing. This in particular is used explain the common religious and grandiose content of psychotic experiences and the belief in supernatural powers, which may have been believed rather than disbelieved in traditional societies. The onset of schizophrenia also closely resembles shamanic initiations, which often feature hallucinations, delusions and incoherent speech. Possible links between shamanism and insanity have been recognised for many decades by anthropologists (e.g. "...mentally ill people are often regarded as holy in primitive societies" and "Feeblemindedness is treated with scorn in Niue today, but insanity still calls forth respect") but the most recent iteration of the theory is by Joseph Polimeni, who argues that shamans facilitate group functioning, and so psychosis evolved as a result of group selection. Critics have argued that the trance states and self-control exhibited by shamans are unlike the characteristics of schizophrenia.


Attention Deficit Hyperactivity Disorder (ADHD)

Attention-Deficit/Hyperactivity Disorder explores the origins of mental disorders by considering how certain traits may have been advantageous in ancestral environments. Attention-Deficit/Hyperactivity Disorder (
ADHD Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple ...
) is examined within an Evolutionary psychiatry framework understands why behaviors associated with the disorder persist in the human population. One hypothesis suggests that traits like hyperactivity, impulsivity, and novelty-seeking were beneficial for hunter-gatherer societies. These characteristics could enhance survival by promoting exploration, quick decision-making, and adaptability in changing environments. The “hunter versus farmer” theory posits that while such traits were advantageous for nomadic hunters, they became less suitable with the advent of sedentary agricultural societies, leading to conflicts with modern social structures and expectations. Proponents of this view argue that ADHD behaviors are not inherently pathological but are mismatches between ancient adaptive traits and contemporary environments. This argument fits into larger idea of neurodiversity and encourages a reevaluation of ADHD, promoting understanding and adaptation rather than solely focusing on symptom management. Some psychiatrists have even begun to cater to evolutionary framework of ADHD. Critics caution that evolutionary explanations may oversimplify the complex interplay of genetic, environmental, and neurodevelopmental factors that contribute to ADHD. They emphasize the importance of evidence-based approaches in diagnosis and treatment, noting that while evolutionary theories provide interesting insights, they should not replace established scientific methodologies. Though the enticing idea that ADHD was once advantageous is catching up in media.


Autism spectrum disorder (ASD)

Autism spectrum disorder Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing di ...
is characterized by difficulties with social interaction and communication, and restricted and repetitive behavior. In developed countries, about 1.5% of children are diagnosed with ASD , up from 0.7% in 2000 in the United States. It is diagnosed four-to-five times more often in males than females. Autism differs widely between individuals (it is highly heterogenous) with different causes for different individuals. Some cases are caused by deleterious mutations or prenatal and neonatal trauma, for which no adaptive explanation is required. These cases are often associated with
intellectual disability Intellectual disability (ID), also known as general learning disability (in the United Kingdom), and formerly mental retardation (in the United States), Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010).Archive is a generalized neurodevelopmental ...
. Estimates range that between 5–20% of the autism spectrum can be explained by these dysfunctional processes, especially of genetics. However, other cases of autism are eligible for adaptive explanations. The fact that multiple explanations for autism exist causes conflict within the autism community, especially between proponents of the
neurodiversity The neurodiversity paradigm is a framework for understanding human brain function that considers the diversity within sensory processing, Motor skill, motor abilities, Social anxiety, social comfort, cognition, and Attention, focus as neurobiol ...
perspective and family members caring for individuals with ASD that have severe disabilities. The idea of autism as conveying cognitive strengths has become steadily more popular since the film
Rain Man ''Rain Man'' is a 1988 American road movie, road comedy-Drama (film and television), drama film directed by Barry Levinson and written by Barry Morrow and Ronald Bass. It tells the story of abrasive and selfish wikt:wheeler-dealer, wheeler-dea ...
and the recent growth of the
neurodiversity The neurodiversity paradigm is a framework for understanding human brain function that considers the diversity within sensory processing, Motor skill, motor abilities, Social anxiety, social comfort, cognition, and Attention, focus as neurobiol ...
and
autism rights movement The autistic rights movement, also known as the autism acceptance movement, is a social movement allied with the disability rights movement. It emphasizes the neurodiversity paradigm, viewing autism as a set of naturally occurring variations in ...
s, although recognition of unusual autistic ability be found even in the early writings of
Hans Asperger Johann Friedrich Karl Asperger (, ; 18 February 1906 – 21 October 1980) was an Austrian physician. Noted for his early studies on atypical neurology, specifically in children, he is the namesake of the former autism spectrum disorder Asperger ...
who called his autistic patients 'little professors'. It has been suggested by autistics such as
Temple Grandin Mary Temple Grandin (born August 29, 1947) is an American academic, inventor, and ethologist. She is a prominent proponent of the humane treatment of livestock for slaughter and the author of more than 60 scientific papers on animal behavior. ...
that autistic hunter-gatherer ancestors were important figures in the community, especially for their inventive capacity: Leading autism researcher
Simon Baron-Cohen Sir Simon Philip Baron-Cohen (born 15 August 1958) is a British clinical psychologist and professor of developmental psychopathology at the University of Cambridge. He is the director of the university's Autism Research Centre and a Fellow of ...
has proposed that autism is an extreme systemising cognitive type, on an empathising-systemising spectrum which all people fall onto, somewhat related to the things-people dimension of interests. He recognised the exceptional talent of many autistic people in some area of non-human knowledge or skill. In his book, ''"The Pattern Seekers: how autism drives human invention"'', he proposes a theory of human inventiveness that places autistic individuals as having extreme versions of these inventing (or systemising) traits. Marco del Giudice has suggested autistic-like traits in their non-pathological form contribute to a male-typical strategy geared toward high parental investment, low-mating effort, and long-term resource allocation. He has also related this to a slow life history strategy. This is based on the fact that autistics show lower interest in short-term mating, higher partner-specific investment, and stronger commitment to long-term romantic relations. Bernard Crespi has suggested that autism is a disorder of high intelligence, noting that autism commonly involves enhanced, but imbalanced, components of intelligence. This hypothesis is supported by evidence showing that autism and high IQ share a diverse set of convergent correlates, including large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, profession and occupational interests in engineering and physical sciences, and high levels of positive assortative mating. Recent evolutionary selection pressures for high intelligence in humans have therefore conveyed autism risk.


Antisocial personality disorder

Antisocial personality disorder (sometimes known as sociopathy or
psychopathy Psychopathy, or psychopathic personality, is a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits. These traits are often masked by superficial charm and immunity ...
), is characterised by deceitfulness, lack of empathy and guilt, impulsiveness, and antisocial behaviour. The prevalence of psychopathy in the general population is estimated to be around 1%, and 20% in prison populations with higher rates in
North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
than
Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
. Psychopathy,
narcissism Narcissism is a self-centered personality style characterized as having an excessive preoccupation with oneself and one's own needs, often at the expense of others. Narcissism, named after the Greek mythological figure ''Narcissus'', has evolv ...
and
Machiavellianism Machiavellianism may refer to: *Machiavellianism (politics), the political philosophy of Niccolò Machiavelli, usually associated with various forms of political realism. *Machiavellianism (psychology), a scale in personality psychology that meas ...
are considered to be part of the
Dark Triad The dark triad is a psychological theory of personality, first published by Delroy L. Paulhus and Kevin M. Williams in 2002, that describes three notably offensive, but non-pathological personality types: Machiavellianism, sub-clinical narcissi ...
, traits that are generally characterised by selfishness and low agreeableness. Various evolutionary hypotheses have been proposed to explain psychopathy and the Dark Triad. Within an ancestral context, high self-interest and low levels of empathy could function as a short-term mating strategy. There is evidence that Dark Triad traits are positively correlated with the number of sexual partners, more unrestrictive
sociosexuality Sociosexuality, sometimes called sociosexual orientation, is the individual difference in the willingness to engage in sexual activity outside of a committed relationship. Individuals who are more ''restricted'' sociosexually are less willing to en ...
and preference for short-term mates. Glenn et al. stated two theories on how selection might allow for psychopathic traits. The first is as a fast
life-history Life history may refer to: * Life history theory Life history theory (LHT) is an analytical frameworkVitzthum, V. (2008). Evolutionary models of women's reproductive functioning. ''Annual Review of Anthropology'', ''37'', 53-73 designed to stud ...
strategy, associated with less focusing on the future, high risk taking and short-term mating. The second is mutation-selection balance, with many common
allele An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), ...
s of small effect selected against, which, when accumulated, can result in psychopathic behaviour, without any significant disruption of
reproductive fitness Fitness (often denoted w or ω in population genetics models) is a quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals ...
. Mealey's influential account states that psychopaths are designed for social deception and evolved to pursue manipulative life strategies or cheating strategies, (reflected in cheater-cooperation models of
game theory Game theory is the study of mathematical models of strategic interactions. It has applications in many fields of social science, and is used extensively in economics, logic, systems science and computer science. Initially, game theory addressed ...
). Cheating strategies are stable at low frequencies in the population, but will be detected and punished at higher frequencies. This frequency-dependent strategy would explain the prevalence of psychopathic traits in the population. Mealey makes four statements about psychopathy: # There is a genetic predisposition for psychopathy, which is normally distributed in all populations. # A few individuals will be deemed "
morally Morality () is the categorization of intentions, decisions and actions into those that are ''proper'', or ''right'', and those that are ''improper'', or ''wrong''. Morality can be a body of standards or principles derived from a code of conduc ...
insane" in any
culture Culture ( ) is a concept that encompasses the social behavior, institutions, and Social norm, norms found in human societies, as well as the knowledge, beliefs, arts, laws, Social norm, customs, capabilities, Attitude (psychology), attitudes ...
, due to selection filling in this small and frequency-dependent niche. # Depending on environmental conditions, individuals who are less extreme on the continuum will pursue a similar cheating strategy. # An underlying genetic continuum of psychopathy is present in all of us, becoming apparent when antisocial strategies are more profitable in certain conditions. Mealey also explains the higher male prevalence and predisposing environmental factors (low physical attractiveness, age, health, physical attractiveness, intelligence, socioeconomic status, and social skills) as signals that a cheating strategy is preferable, hence why these factors are associated with psychopathic traits.


Depression

Major depressive disorder Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive depression (mood), low mood, low self-esteem, and anhedonia, loss of interest or pleasure in normally ...
(MDD) is characterized by at least two weeks of persistent low mood. It is accompanied by a wide variety of negative feelings such as
low self-esteem Self-esteem is confidence in one's own worth, abilities, or morals. Self-esteem encompasses beliefs about oneself (for example, "I am loved", "I am worthy") as well as emotional states, such as triumph, despair, pride, and shame. Smith and Macki ...
, loss of interest in normally enjoyable activities and low energy. There are multiple possible evolutionary explanations for the occurrence of depression and low mood in humans. Many different hypotheses are not
mutually exclusive In logic and probability theory, two events (or propositions) are mutually exclusive or disjoint if they cannot both occur at the same time. A clear example is the set of outcomes of a single coin toss, which can result in either heads or tails ...
. It has been suggested that different life events and other disease processes are responsible for different forms of depression with subtypes related to infection, long-term stress, loneliness, traumatic experience, hierarchy conflict, grief, romantic rejection, postpartum events, the season, chemicals, somatic diseases and starvation. Individualising treatment based on causational subtypes is suggested as lending direction in treatments. Other hypotheses include:


Social-oriented hypotheses

The social competition hypothesis (similarly to the social rank theory) interprets depression as an emotion of submission, an involuntary strategy to create a subjective sense of incapacity. Feelings of powerlessness or helplessness cause this incapacity, inhibiting aggression towards higher-ranked people and signalling submission. Low mood encourages acceptance of a loss in rank and promotes yielding. John Price endorsed this theory, noting that chickens who lose a fight withdraw from social engagement and act submissively, reducing further attacks by chickens higher in the hierarchy and avoiding being wounded or even killed. Similar to the social competition hypothesis, the 'social risk hypothesis' states that depression prevents people engaging in social interactions which might lead to them being ostracised. This hypothesis is inspired by risk-sensitive foraging. It suggests that people in successful
social relation A social relation is the fundamental unit of analysis within the social sciences, and describes any voluntary or involuntary interpersonal relationship between two or more conspecifics within and/or between groups. The group can be a language or ...
ships can tolerate higher levels of social risk-taking, while on the other hand, people with low social standing cannot. The theory suggests that the low mood which accompanies MDD exists in order to reduce potential risk taking and encourages isolation in those individuals.


Psychic pain hypotheses

Depression is common in people who are pursuing unreachable goals and depression might be a manifestation, similarly to the social competition hypothesis, of a failure to yield. Low mood increases an organism's ability to cope with the adaptive challenges characteristic of unpropitious situations. Pessimism and lack of motivation may give a fitness advantage by inhibiting certain actions. When current life plans are not working, the distress and lack of motivation that characterize depression may motivate planning and reassessment or escape, even by
suicide Suicide is the act of intentionally causing one's own death. Risk factors for suicide include mental disorders, physical disorders, and substance abuse. Some suicides are impulsive acts driven by stress (such as from financial or ac ...
. Feelings of sadness and discouragement may be a useful stimulus to consider ways of changing the situation, by disengagement of motivation from an unreachable goal. In nature, it would make sense to decrease motivation in situations where taking action would be futile and therefore a waste of resources. Therefore, low mood in those situations would help the individual to preserve energy. This hypothesis is inspired by the
marginal value theorem The marginal value theorem (MVT) is an optimality model that usually describes the behavior of an optimally foraging individual in a system where resources (often food) are located in discrete patches separated by areas with no resources. Due to t ...
. The 'analytical rumination' hypothesis is a refinement of the psychic pain hypothesis. It suggests that depressive symptoms are triggered by complex problems and an inability to find the correct course of action. This theory describes how this could lead to a loss of interest in virtually all activities in order to benefit the individual to single-mindedly focus on the problem at hand.


Cry-for-help and bargaining hypotheses

Depression, deliberate
self-harm Self-harm refers to intentional behaviors that cause harm to oneself. This is most commonly regarded as direct injury of one's own skin tissues, usually without suicidal intention. Other terms such as cutting, self-abuse, self-injury, and s ...
and
suicide Suicide is the act of intentionally causing one's own death. Risk factors for suicide include mental disorders, physical disorders, and substance abuse. Some suicides are impulsive acts driven by stress (such as from financial or ac ...
may be reactions to life circumstances that encourage others to provide resources and help to the depressed or suicidal individual. Group members, and especially family members, have a vested interest in keeping the depressed individual alive and changing their circumstances in such a way as to make them a functioning member of society again. It may be the case that certain life choices (e.g. marrying somebody who your parents dislike) may become possible only when depressed or suicidal behaviour is observed by the family or social group. This could explain various precipitating factors for depression. However, some research has found that signs of depression only lead to a short-term increase of care by family members, after which they tend to withdraw.


Eating disorders

Evolutionary perspectives exist on
Anorexia nervosa Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. Individuals wit ...
(henceforth 'anorexia') and
Bulimia nervosa Bulimia nervosa, also known simply as bulimia, is an eating disorder characterized by binge eating (eating large quantities of food in a short period of time, often feeling out of control) followed by compensatory behaviors, such as self-indu ...
(henceforth 'bulimia'). Anorexia is characterized by restriction of food intake, bulimia by cycles of binging (excessive eating) and purging (forced removal of the food). Both are associated with fear of weight gain, body image disturbance, and physical attractiveness concerns. The Sexual Competition Hypothesis relates eating disorders to body shape and physical appearance as of adaptive function in human females (who are highly over-represented in eating disorders): eating disorders are supposed to increase female attractiveness. Some evidence from non-clinical and clinical populations support this hypothesis. They apply the framework of life-history theory, proposing anorexia as a slow life history strategy whilst bulimia is a fast strategy. Both studies had their limitations and it was further mentioned that the deep structures of eating disorders may not be reflected by their current classifications. An alternative account comes from Nesse. Recognising that many anorexia patients are neither actively chasing men nor particularly interested in sex, and that eating disorders became more common in the second half of the 20th century, he argues eating disorders are new problems with no redeeming features. They are caused by increasingly high concerns about appearance linked with the possibility in modern societies to compare someone's appearance to thousands of others instantly. Glorification of unrealistic body types in media, as well as increased availability of sex, may contribute to this. He does, however, acknowledge that intra-sexual competition is a driving force of anorexia and bulimia in undergraduate women.
Obesity Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...
is not an eating disorder in any classification system, though it is established that overweight and obesity in particular is connected with various diseases, and an evolutionary perspective can explain the tendency towards overeating. The human body has evolved to cope with the environments of scarcity, selecting for beneficial adaptations of hunger and eating. Fat storage allows preparation for future food shortages. In a case of mismatch, modern environments have cheap, readily available food, and very few times of scarcity. Kardum et al. also elaborated the differences in nutrient composition in modern and ancestral societies to illustrate the challenge modern diet imposes on the not-yet adapted human body and genotype.


Anxiety

Anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
is a feeling of worry, unpleasantness and dread towards possible future events and exists to protect us from dangers. In the US,
anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...
s are the most common mental illness, with around 29% of adults expected to have any anxiety disorder in their lifetime. Women are disproportionately affected. Evolutionary perspectives on anxiety disorders generally consider the adaptive function of the emotion of normal anxiety, and reasons this adaptive system may manifest in the various types of anxiety disorder. A key evolutionary explanation for anxiety disorder is the Smoke Detector Principle. It is often preferable to overactivate anxiety in dangerous situations, in the same way a smoke detector is designed to overactivate. Randolph Nesse writes:Next to normal anxiety there are multiple types of anxiety disorders which are all characterised by excessive fear and anxiety. These disorders include:
specific phobias Specific phobia is an anxiety disorder, characterized by an extreme, unreasonable, and irrational fear associated with a specific object, situation, or concept which poses little or no actual danger. Specific phobia can lead to avoidance of the o ...
(e.g.,
agoraphobia Agoraphobia is an anxiety disorder characterized by symptoms of anxiety in situations where the person perceives their environment to be unsafe with no way to escape. These situations can include public transit, shopping centers, crowds and q ...
),
generalized anxiety disorder Generalized anxiety disorder (GAD) is an anxiety disorder characterized by excessive, uncontrollable and often irrational worry about events or activities. Worry often interferes with daily functioning. Individuals with GAD are often overly con ...
,
social anxiety disorder Social anxiety disorder (SAD), also known as social phobia, is an anxiety disorder characterized by sentiments of fear and anxiety in social situations, causing considerable distress and impairing ability to function in at least some asp ...
,
separation anxiety disorder Separation anxiety disorder (SAD) is an anxiety disorder in which an individual experiences excessive anxiety regarding separation from home and/or from people to whom the individual has a strong emotional attachment (e.g., a parent, caregive ...
,
panic disorder Panic disorder is a mental disorder, specifically an anxiety disorder, characterized by reoccurring unexpected panic attacks. Panic attacks are sudden periods of intense fear that may include palpitations, sweating, shaking, shortness of breath ...
, and
selective mutism Selective mutism (SM) is an anxiety disorder in which a person who is otherwise capable of speech becomes unable to speak when exposed to specific situations, specific places, or to specific people, one or multiple of which serve as triggers. Se ...
.


Treatment

Evolutionary psychiatry has so far primarily concentrated on scientific explanations for mental disorders rather than developing novel treatment approaches. However, there are various consequences of taking an evolutionary perspective on mental disorder for treatment decisions, at an individual and public health level, which make evolutionary psychiatry an important field of future research and application. Evolutionary explanations for disorders which reframe them as mismatched or otherwise costly adaptations may be taken to imply that treatment is unnecessary – but this is not the view of evolutionary psychiatrists – and is the same mistake made by those who believe evolutionary biology means endorsing
eugenics Eugenics is a set of largely discredited beliefs and practices that aim to improve the genetic quality of a human population. Historically, eugenicists have attempted to alter the frequency of various human phenotypes by inhibiting the fer ...
, a version of the
naturalistic fallacy In metaethics, the naturalistic fallacy is the claim that it is possible to define good in terms of merely described entities, properties, or processes such as ''pleasant'', ''desirable'', or '' fitness''. The term was introduced by British phil ...
– that what is natural (in this case, evolved) is good. Many medical interventions are 'unnatural' in this sense (e.g.
contraception Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only be ...
and
anaesthetic An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into t ...
). The explanations of evolutionary psychiatry have no inherent value in directing treatment. Randolph Nesse writes: Although evolutionary explanations may not affect the necessity for treatment, they can be directive or supportive of treatment, or make current treatment strategies more effective. Proposed benefits of taking an evolutionary perspective on mental disorders have largely come from integrating evolutionary explanations into psychotherapy. Bailey and Gilbert write:It has been suggested that patients are encouraged and destigmatised by hearing evolutionary explanations for their conditions, with positive effects during cognitive behavioural therapy – integration of knowledge of behavioural genetics, neuroscience and evolutionary psychiatry into psychotherapy has been called 'Informed Cognitive Therapy' by Mike Abrams. Abrams also proposes that recognising the inherited and somewhat immutable nature of certain traits (such as
psychopathy Psychopathy, or psychopathic personality, is a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits. These traits are often masked by superficial charm and immunity ...
and
autism Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing d ...
) implies that therapists should not try and alter the traits characteristics, but instead provide advice on how to best utilise these cognitive types within the context of modern society. This aligns with the aims and claims of the
neurodiversity The neurodiversity paradigm is a framework for understanding human brain function that considers the diversity within sensory processing, Motor skill, motor abilities, Social anxiety, social comfort, cognition, and Attention, focus as neurobiol ...
movement. Evolutionary explanations for mental disorders, especially of mismatch, have connotations for
public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the de ...
measures and organisational psychology. Disorders which are consequences of novel environments may be rectified or prevented by implementing social structures which better replicate ancestral environments. For example,
postpartum depression Postpartum depression (PPD), also called perinatal depression, is a mood disorder which may be experienced by pregnant or postpartum women. Symptoms include extreme sadness, low energy, anxiety, crying episodes, irritability, and extreme cha ...
may be more likely in modern environments where single parents are given sole responsibility in raising a child, which is highly unusual in the context of an evolutionary history of
alloparenting Alloparenting (or alloparental care) is a term for any form of parental care provided by an individual towards young that are not its own direct offspring. These are often called "non-descendant" young, even though grandchildren can be among them ...
and communal care. Reversing this mismatch, social services supporting new mothers in parenting may prevent postpartum depression (''see Evolutionary approaches to postpartum depression'').
Education Education is the transmission of knowledge and skills and the development of character traits. Formal education occurs within a structured institutional framework, such as public schools, following a curriculum. Non-formal education als ...
and employment environments which are particularly likely to cause mental disorders may also be altered to better suit natural human psychological capacities.


References

{{Digital media use and mental health Evolutionary psychology Psychiatric research