Any activity is instinctive if it is conducted without prior experience (that is, without learning) and is thus a manifestation of intrinsic biological components. Sea turtles that hatch on a beach will automatically go to the ocean. Deer eat plants because that's where they grow; they don't think about it or decide to do it. This type of behavior is called an instinct.
Instincts can also be learned through experience. A deer that has never eaten anything but grass will eventually learn not to eat it. If it encounters people, dogs, cars, etc., it will avoid these things like the plague. This type of learning is called conditioning. Conditioning works by connecting events that have an emotional value with something that produces a response (in this case, avoiding pain).
Some instincts are more developed in some animals than others. Deer have very good senses of smell and hearing but less-developed eyesight. This means that they are more likely to escape danger if they don't have to see it coming. Turtles, on the other hand, have very good vision so they need to learn what not to do.
Sea turtles that hatch on a beach will instinctively swim to open water but they cannot yet control their limbs well enough to make it there on their own. They must wait until they develop motor skills before they can move away from the safety of the beach.
A stereotyped, or generally unvarying, behavior that is typical of a given species is referred to as an instinct. An intuitive activity does not need to be taught; it is completely functioning the first time it is performed. Most instincts are very useful for survival of the organism as a whole (for example, fleeing from a threat) but some are only beneficial in the context of the organism's history (for example, nesting). Some instincts may have been beneficial at one time in our evolutionary history but no longer are (for example, hunting as a way of life). Regardless, all instincts are hard-wired into our brains and cannot be ignored or removed.
Instinctual behaviors are those which are automatically initiated without much thought or preparation on the part of the animal. Instincts are responsible for such actions as sleeping, eating, fighting off predators, etc. The word "instinct" comes from the Latin instigare meaning "to set in motion". Thus, an instinct is a set of procedures that guide certain actions of an organism without requiring analysis of the environment or consideration of the outcome of these actions. All animals, including humans, have instincts. While some instincts are helpful for survival, others can be detrimental or even fatal in the right situation.
Theory of Instinct In biology, an instinct is a species-specific pattern of behavior that is not taught. Because of the evident importance of learning in molding all kinds of human conduct, this view—that human behavior is governed by instincts—has attracted a significant amount of criticism. The classic work on this subject was called The Descent of Man, which was written by Charles Darwin. He argued that humans share many innate behaviors with other animals, but also have the ability to learn new behaviors through experience.
Modern researchers generally agree with Darwin that our behaviors are shaped by inherited traits and by learning, but they add that the effects of these two factors are likely to be stronger than what Darwin suggested. His theory has been updated over time to take into account new findings from neuroscience and evolutionary psychology. For example, recent research has shown that even young infants are able to detect similarities between objects they have seen before and things they have not. This ability, which helps them learn about the world around them more quickly, is called "inference" in psychologists' terms. It seems clear that this skill comes naturally to humans, rather than being learned through experience.
In addition to inference skills, research shows that humans tend to repeat behaviors that produced positive results in the past. This tendency, which is called "repetition priming", is thought to help us avoid wasting energy by not acting like something that has never been done before.