From ArticleWorld

Instinct is the result of generations of evolution and usually refers to inherited patterns of behaviour. It is the initial, pre-intellectual response to a stimulus that dictates behaviour unless, or until, intelligence takes over and modifies the action. Bodily functions such as the sex drive and emotions are largely instinctual as they are biologically determined. Instinct is more easily observable in animals when they perform an action for the first time such as courtship or fighting which is not based on experience.

Instincts, or Fixed Action Patterns, are initiated when what are known as Key Stimuli lead to Innate Releasing Mechanisms. Hormones are instrumental in carrying the messages which lead to the reactions.


According to Darwin’s theory of evolution, not all instincts make it through the passing of time but only those which improve the chances of survival in some way. Like a self-fulfilling prophecy, instincts which improve survival become stronger and so are then passed down the generations which survive due to their instincts in a process known as evolutionary biology.

In 1896, James Baldwin maintained that organisms could also adjust to changing circumstances during their own lifetime by acquiring ‘phenotypic plasticity’. One example of this is the increased muscle strength acquired through regular exercise.

Human Instincts

According to psychoanalysts, instinct refers to motivational forces such as sex and aggression or what some call a ‘killer instinct.’ Sex and aggression are also referred to as the life and death instinct. The traits that are free of conditioning and environmental influences such as altruism and disgust are also considered instincts as are language acquisition and face recognition.