Human Nature

Ethology (from Greek: ἦθος, ethos, "character"; and -λογία, -logia, "the study of") is the scientific study of animal behavior, and a sub-topic of zoology.

http://en.wikipedia.org/wiki/Ethology

Instincts are the inherent inclination of a living organism toward a particular behavior. The fixed action patterns are unlearned and inherited. The stimuli can be variable due to imprinting in a sensitive period or also genetically fixed. Examples of instinctual fixed action patterns can be observed in the behavior of animals, which perform various activities (sometimes complex) that are not based upon prior experience, such as reproduction, and feeding among insects. Sea turtles, hatched on a beach, automatically move toward the ocean, and honeybees communicate by dance the direction of a food source, all without formal instruction.

http://en.wikipedia.org/wiki/Instinct

Human nature is the concept that there is a set of inherent distinguishing characteristics, including ways of thinking, feeling and acting, that all humans tend to have.

The questions of what ultimately causes these distinguishing characteristics of humanity and how this causation works, and how fixed human nature is, are amongst the oldest and most important questions in western philosophy. These questions have particularly important implications in ethics, politics and theology because human nature is seen as providing standards or norms that humans can use when judging how best to live either as individuals, or members of a community. The complex implications of such discussion are also often themes which are dealt with in art.

http://en.wikipedia.org/wiki/Human_nature

Andy Horton (me) surmises that human beings have an inherent cognitive way of thinking that varies according to personality. Behaviour does not follow from thinking because of social constraints. Also, humans have a ability to change their cognition if they want to.