The psychologist's fallacy is an
informal fallacy
Informal fallacies are a type of incorrect argument in natural language. The source of the error is not just due to the ''form'' of the argument, as is the case for formal fallacies, but can also be due to their ''content'' and ''context''. Fallac ...
that occurs when an observer assumes that his or her subjective experience reflects the true nature of an event. The fallacy was named by
William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher and psychologist. The first educator to offer a psychology course in the United States, he is considered to be one of the leading thinkers of the late 19th c ...
in the 19th century:
Alternative statements of the fallacy
Some sources state the psychologist's fallacy as if it were about two ''people''—the observer and the observed—rather than about one observer and a fact. For example,
In this alternative form, the fallacy is described as a specific form of the "similar to me" stereotype: what is unknown about another person is assumed, for simplicity, using things the observer knows about themself. Such a bias leads the observer to presuppose knowledge or skills, or lack of such, possessed by another person. For example, "I (or everyone I know or most people I know) don't know very much about chemistry. Therefore I can assume that this other person knows very little about chemistry." This assumption may be true in any number of specific cases, making
inductive reasoning
Inductive reasoning refers to a variety of method of reasoning, methods of reasoning in which the conclusion of an argument is supported not with deductive certainty, but with some degree of probability. Unlike Deductive reasoning, ''deductive'' ...
based on this assumption cogent, but is not applicable in the general case (there are many people who are very knowledgeable in the field of
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 ...
), and therefore
deductive reasoning
Deductive reasoning is the process of drawing valid inferences. An inference is valid if its conclusion follows logically from its premises, meaning that it is impossible for the premises to be true and the conclusion to be false. For example, t ...
based on this assumption may be invalid.
These alternative statements, however, do not match what
William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher and psychologist. The first educator to offer a psychology course in the United States, he is considered to be one of the leading thinkers of the late 19th c ...
characterized when he named the fallacy.
Examples from literature
Victor Frankl (1946) "Man's Search for Meaning":
See also
*
Historian's fallacy
The historian's fallacy is an informal fallacy that occurs when one assumes that decision makers of the past viewed events from the same perspective and having the same information as those subsequently analyzing the decision. It is not to be confu ...
*
Mind projection fallacy
The mind projection fallacy is an informal fallacy first described by physicist and Bayesian philosopher E. T. Jaynes. In a first, "positive" form, it occurs when someone thinks that the way they see the world reflects the way the world real ...
References
1890 introductions
Informal fallacies
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