Instinct Theory

Type of psychology: Motivation
Fields of study: Biological influences on learning; motivation theory
Until behaviorism, which rejected instincts, became the dominant theoretical model for
psychology during the early decades of the twentieth century, instinct theory was often
used to explain both animal and human motivation. As behaviorism faded, aspects of
instinct theory returned to psychology—modernized, but still recognizable as parts of
the oldest theory of motivation.

Key concepts
• behaviorism
• instinct
• motivation
• reflex
• scientific method
• tropism

When instinct theory was incorporated into the new scientific psychology of
the late nineteenth century, it was already centuries old. In its earliest form,
instinct theory specified that a creature’s essential nature was already established
at birth and that its actions would largely be directed by that nature. A
modern restatement of this notion would be that, at birth, creatures are already
programmed and that they must operate according to their programs.
Charles Darwin’s theory of evolution through natural selection, first published
in 1859, led to great controversy in the late nineteenth and early twentieth
centuries. It also fostered speculation that, if humans were evolved
from earlier forms and were therefore more closely related to other animals
than had once been believed, humans might have instincts—inherited behaviors—
as other animals were observed to have. William McDougall was
one of the main early instinct theorists; he suggested a list of human instincts
in 1908 that included such varied behaviors as repulsion, curiosity,
self-abasement, and gregariousness. Many researchers came up with their
own lists of human instincts; by the 1920’s, more than two thousand had
been suggested.

A computer program can be printed out and studied, but an instinct in
the original sense cannot so easily be made explicit. At best, it can be inferred
from the behavior of an animal or person after other explanations
for that behavior have been discounted. At worst, it is simply assumed from
observing behavior. That a person has, for example, an instinct of argumentativeness
could be assumed from the person’s arguing; arguing is then “explained”
by declaring that it comes from an instinct of argumentativeness.
Such circular reasoning is unacceptable in scientific analyses, but it is very
common in some early scientific (and many modern, popular) discussions