Instinct is the automatic pattern of behavior with which all animals are endowed except human beings.
An animal does not need to discover how to live, its instinct guarantees that its behavior will fulfill the requirements of its nature. An animal automatically seeks the kind of food it needs and evades that which would be harmful to it. An animal automatically performs the actions its nature requires, crawling, running, digging holes or burrowing, foraging, grazing, flying, building nests, and all other behavior necessary for its survival and success as the kind of animal it is. An animal does not need to discover any of these things or learn how to do them, it does them automatically as part of its nature. All that an animal does is determined by instinct and it cannot do anything its instinct does not determine or provide a means of doing.
Man Has No Instinct
A human being is not born with any predetermined pattern of behavior or any knowledge of either what his life requires or how to achieve or acquire those requirements. Human beings must discover what they need to live and how to live successfully as human beings. Human beings have no instinct to guide them in any of these things.
Where animals have instinct which provides automatic guidance in all behavior, human beings have minds. All of the automatic behavior an animal's instinct provides, a human must discover and learn. He must learn what a human life requires, what constitutes food and what constitutes poison, what he must do to preserve his body and his health, what kind of shelter he needs and how to provide it.
The reason human beings must learn all these things is because they do not have instinct to determine their behavior. A human being must consciously choose everything he does and choice is impossible without knowledge, knowledge of what there is to choose and knowledge of why one choice is preferable to another.
Ayn Rand beautifully expressed this difference in the instinctive and volitional natures:
"Man comes on earth unarmed. His brain is his only weapon. Animals obtain food by force guided by instinct. Man has no claws, no fangs, no horns, no great strength of muscle, and no instinct to guide him. ... But it is the nature of the rational faculty that it implies choice and the possibility of error. Instinct is infallible within the limits of its sphere. Nature gives an animal both the means and the method of survival; he cannot do wrong in his method; he does what he must; if he is confronted by a fact outside the provisions of his instinct, he can do nothing and he perishes. ... An animal cannot act against his instinct nor suspend it. He enjoys a safety man can never have—the invariable operation of his means of survival. He cannot act against his own nature. Man can. Man can stop his source of existence. Man can choose not to act as a rational being. Man can choose not to function as a man." [The Journals of Ayn Rand, Part 3—Transition Between Novels, "8—The Moral Basis Of Individualism."]
Two very important observations are made by Rand here. The first has much more significance than might be recognized. Every creature's physical nature exactly fits the requirements of its behavioral nature. The animals whose instinctive method of living is to hunt are provided with the muscles, teeth and claws necessary for that kind of life. The animals whose instinctive method of living is grazing are provided with hooves, and teeth and digestive systems for consuming and digesting vegetable matter, and usually great speed for escaping predators. Every animal, from moles to eagles have the exact physical attributes necessary for living the kind of life their instinct will dictate.
Humans' physical nature also exactly fits the requirements of their behavioral nature. Since their behavior is not determined by instinct they are not provided with any special physical attributes required by any specific behavior. The human physical nature may best be described as adaptable—adaptable to almost any kind of behavior that will be successful when determined by rationally guided choice.
Human beings are not provided with any natural covering, like most animals. Instead they use their minds to discover how to make their own clothing which is unlimited in both design and utility. Humans are not provided with exceptional strength or speed. Instead they design engines, and build vehicles that are more powerful and faster than any animals, and adapt those machines to their tastes and comfort. Humans are not provided with any special ability to build nests, dig dens, or any other kind of shelter. Instead they learn how to use almost all of natures materials to build everything from simple homes to skyscrapers.
The second observation Rand made was that an instinctive creature cannot act contrary to the requirements of its own nature. Only a creature with volitional consciousness must choose to live as his nature requires, or can choose to live as less than a human being. That is exactly what many, perhaps most, human beings do.
Why Some Want Instinct To Be True
Ayn Rand never rejected or accepted the evolutionary hypothesis, but uses it to illustrate the nature of a human being who fails to choose to be fully human:
"There is an enormous breach of continuity between man and all the other living species. The difference lies in the nature of man's consciousness, in its distinctive characteristic: his conceptual faculty. ... the development of a man's consciousness is volitional: no matter what the innate degree of his intelligence, he must develop it, he must learn how to use it, he must become a human being by choice. What if he does not choose to? Then he becomes a transitional phenomenon—a desperate creature that struggles frantically against his own nature, longing for the effortless "safety" of an animal's consciousness [instinct], which he cannot recapture, and rebelling against a human consciousness, which he is afraid to achieve."
[Emphasis mine.] [The Ayn Rand Letter, Vol. II, No. 17 May 21, 1973, "The Missing Link--Part II"]
Many actually want there to be instinct, because they do not want to be or are afraid of being totally responsible for their own choices. They long for the safety of an instinctive nature that makes choices for them, and relieves from the fact that what they are is the consequence of their own choices and actions. They believe, like those who want to blame other things like heredity, or circumstances, or society, for what they are, that they are relieved of responsibility for what they do—"instinct made them do it."
I've quoted Rand from one of her journals and from a letter, but she made this same point about instinct in her much more well known, Atlas Shrugged as well.
"Man has no automatic code of survival. His particular distinction from all other living species is the necessity to act in the face of alternatives by means of volitional choice. He has no automatic knowledge of what is good for him or evil, what values his life depends on, what course of action it requires. Are you prattling about an instinct of self-preservation? An instinct of self-preservation is precisely what man does not possess. An 'instinct' is an unerring and automatic form of knowledge. A desire is not an 'instinct A desire to live does not give you the knowledge required for living. And even man's desire to live is not automatic: your secret evil today is that that is the desire you do not hold. Your fear of death is not a love for life and will not give you the knowledge needed to keep it." [For The New Intellectual, from Atlas Shrugged, "This is John Galt Speaking."]
Why Instinct Is Wrongly Attributed to Human Beings
There are several reasons why instinct is mistakenly attributed to the nature of human beings.
The most common reason is that people don't really understand what instinct is. They do not understand that instinct is a total and complete program of behavior for those creatures that have it. Instinctive creatures do not choose their behavior, they behave as their instinct dictates.
A worse mistake, perhaps, is the belief that human beings are some kind of chimera, a mixture of instinct and reason, but instinct and volition are mutually exclusive. Volition is that aspect of human consciousness that requires every thought or action to be consciously chosen. Though some people insist human beings have instinct as well as volition, in reality, no one actually believes that.
When an animal does something, even when it kills a human being or destroys property, no one believes the animal is morally culpable, even when the animal is considered dangerous enough to put down. The reason animals are not regarded as morally responsible is because morality assumes the ability to consciously choose. It is because what animals do is determined by their instinctive nature that they are considered essentially amoral, not morally responsible for their actions. Human beings are considered morally responsible because they do choose what they do. If what human beings did was determined by instinct, even only partly, how could they be considered responsible for what they do? They couldn't. But, in fact, everyone knows human beings are responsible for their actions, because they do choose them, and nothing but their own choices determines what they do.
Another common reason instinct is attributed to human beings is simply a mistake. Certain biological functions, like the functions of the autonomic nervous system are mistaken for instinct. Yawning, blinking, coughing, sneezing, an infant's "sucking," and other reflexes are all sometimes wrongly called "instinct." These are all physiological in nature and are shared by most advanced animals, with the exception that human beings actually have some volitional control over some of these functions. Instinct only pertains to that behavior in animals that in human beings would require conscious choice.
Though human beings do not have instinct, even when presented with the evidence, there are some who stubbornly cling to the idea they do. They are the one's Ayn Rand described as rebelling against their own rational volitional nature, terrified of being totally responsible for everything they think and do. Though there is no way they can truly "recapture" the safety of an animals [instinctive] consciousness, they believe they can substitute those aspects of their nature they do not directly control, their emotions, feelings, fears, desires, superstitions, and whims for instinct (and may even call them instinct). Of course it doesn't work, because the only means one has for determining what is right or wrong, good or bad, is the rational mind. The feelings are irrational and non-cognitive and the individual who surrenders to his feelings ends up a slave to feelings and desires he knows neither the reason for or cause of, and to the extent he is driven by irrational feelings he is less than human and incapable of any real human success or happiness.
[NOTE: I've quoted Ayn Rand at length in this article, not as an authority, but is the supremely articulate spokesperson on this issue. Rand made these observations about human nature over forty years ago, but most people, even some of the best philosophers and intellectuals, continue to attribute instinct to human beings today. It is incredible that this mistaken idea about human beings continues to be believed and propagated.]