either: (a) not universal to the species, but a product of particular men's acquired attitudes or beliefs, as in the case
of pugnacity; or (b) the product of learning, as in the case of sexual behavior—which is so simple for the organism
to attain, that virtually all members of the species who develop normally, exhibit it; and/or (c) the product of the
interaction of simple reflexes and learning, as in the case of an infant's sucking behavior.
The concept of "instinct" was first used to account for complex patterns of animal behavior, such as migratory,
mating, and maternal behavior, that appeared inexplicable. But the concept is no less misleading when applied to
animals.
There are, in principle, three categories in terms of which animal behavior can be explained. 1. Actions which are
neurophysiological responses to physical stimuli, i.e., reflexes, and which do not involve the faculty of
consciousness—such as the patellar reflex (knee jerk) in response to tendon stretch. 2. Actions which are guided
directly by an animal's pleasure-pain sensory apparatus, and which involve the faculty of consciousness but not a
process of learning—such as moving toward warmth. (Some students of animal behavior use the term "instinct"
exclusively to designate behavior of this second category; when thus restricted in meaning, the use of the term may
be defensible; but I am inclined to think it inadvisable, in view of the many other meanings historically associated
with the term; at any rate, when I speak of "instinct" in this discussion, I refer to the term as it is commonly used by
clinical psychologists and personality theorists—to cover a good deal more than behavior of this second category.)
- Actions which are the result of learning—such as hunting and fighting. (Sometimes—and this is especially
relevant to allegedly instinctive behavior—the learning is instantaneous, within a given context, and is virtually
inescapable to all normal members of a species; this is "one trial" learning; for instance, avoiding a traumatically
painful stimulus after one encounter.)
Animal behavior that has not been traced to one of these categories, or (more usually) to some combination of
them, has not been explained.^7
The inadequacy of "explanation via instincts" is still more apparent when one considers the complex goal-seeking
activity of man.