Jump to the following topics:
What is instinct? Instinct is a form of guidance which is usually associated with animal behavior; it directs animals in virtually everything that they do -- hunting, mating, building homes (such as nests), etc. The so-called "lower animals" such as insects and reptiles seem to run entirely on the "automatic pilot" of instinct.
Instinct causes, by definition, an unconscious act. Its dynamic goes directly from trigger to action, without the intermediary of "consciousness," which would include such qualities as individuality, freedom of choice, decision-making, volition, and sense of morality. "Instinct thus appears to be almost the opposite of intuition, if the latter is characterized by heightened awareness," said Jagdish Parikh in Intuition: The New Frontier of Management. However, instinct operates from its own type of awareness, viewing the world from its own perspective; it is not the "opposite" of intuition as much as it is a "partner" of intuition, in the overall effort to provide direction to the creature. Perhaps there is a spectrum of awareness, with the poles being automatism and consciousness; our labeling of "lower animals" and "higher animals" (including the humans) seems to be based largely on the position of a species within this particular spectrum. Despite the gap between any animal and humans, we are still part of the spectrum -- not in a category of our own, but merely at the complementary pole from the animals whose behavior seem to be most automatic. The movement toward our end of spectrum introduces other factors:
Some people deny their instincts. Despite the threat to our unfounded pride, we might confess that the ego and will and rationality are rarely (if ever) in full control of our lives. Although we can repress our natural drives (both biological and psychological), those drives express themselves eventually, leading us to do the silly, nonrational, nonlinear (but somehow deeply fulfilling) behaviors which make us genuinely "human." The common reluctance to admit that humans have instincts is generally based on the fallacy that humans are very different from animals, and that we are ideally guided by rationality and (even better) by spirit rather than by mere "animal instinct"; this belief is based less on science (and mere observation) than it is on some people's disdain for their common animality and their fear of "losing control" to the nonrational forces of nature within themselves. However, instinct (like all other parts of ourselves) serves a purpose; on its fundamental level, instinct helps to assure our biological survival (for survival itself, and to maintain our life while we explore our world and our selves and the intermediary of consciousness). And it is a permanent part of the repertoire of tools which allows us to respond to the many types of stimuli and challenges which we encounter -- all of which spur us to become even more conscious and responsive.