All entities... be they living or not... interact with their environment. Rocks weather. Volcanoes erupt. Vines twine. Spiders hunt. Dogs sniff. Humans disrupt. The behaviour of such entities consists of the characteristic set of interactions that they exhibit in the specific circumstances of their environment.

Because of social complexification, humans exhibit a considerably expanded range of behaviours over and above all the biological ones that nature has conferred. As societies respond to the realities of inevitable change, the diversity of roles within it is altered by the evolution of new roles and the extinction of others. Developing a new resource or technological invention will require the acquisition and training of individuals who can perform new roles and demonstrate new behaviours. On the other hand, old technology, the exhaustion of a resource, improved skills or the changing of fashion will bring the redundancy of other roles and the disappearance of their associated behaviours. The weightlifter and the unicyclist symbolize the circus fragility of differing role behaviours. If the public demand for one type of performance disappears, skill transfer to the other is so sufficiently difficult, that redundancy is almost a certainty. Of course there are other roles to consider, but choosing between juggler, lion-tamer, contortionist or trapeze artist is not without serious implications for one's health.

Setting aside those biological reactions that are responses to certain stimuli, the reasons for various behaviours are complex and multilayered in both time and space. One way or another, these 'reasons' usually resolve into individual preferences. Some personal preferences just simply come from direct physical experience... such as a liking for chocolate, a fear of swimming, or an antipathy towards a particular social group. Others... such as a sympathy for the socially deprived, the support for a demented monarch, or the acceptance of dogmatic drivel from institutionalized politics or religion... are the consequences of a nurture that has been confined to an upbringing in particular social circumstances. More rarely, a preference is the result of an individual's research and thought processes that is able to construct a perspective which has a logical coherence to that individual. But whilst it may be claimed that a goal has been chosen for 'logical' reasons... like buying the most efficient car to reduce pollution or bombing a contraceptive factory to prevent war production... the supposedly analytical arguments are rarely universally acclaimed because of the impossibility of getting a set of premises to be generally agreed upon. Under the pressure of close examination, such reasons are likely to be biased by significant personal preference.

There is a widespread assumption extant, consciously or unconsciously held, that by aspiring to certain penultimate goals... like 'fulfilment', 'wealth', 'enlightenment', 'approval', 'dominance', 'salvation', 'ecstasy', etc... and choosing your behaviours accordingly, then an individual may be able to attain an ultimate state of 'happiness' if they reach that goal. There remains much doubt as to the nature of the 'happiness' state, but it is generally thought to be a psychological condition of on-going satisfaction and contentment with ones existential circumstances. There is some evidence to suggest that this has been possible in the past for some of the chosen penultimate goals, but by and large such a condition does not eventuate, because many of these goals simply result in some sort of interim 'satisfaction' which readily dissipates and requires constant renewal. Achilles was not 'happy' with just one killing. Napoleon was never able to be satisfied with the current state of his conquests. Casanova remained unfulfilled no matter how many acts of coitus he was able to indulge in.

However behaviours are selected, none of the consequences of any of the intermediate actions chosen to attain an objective are ever assured. The perturbations and complexity of existence ensure that all chosen behaviours, be they pragmatic, unverified or whatever, do not have determined outcomes. Choosing the pragmatic intermediate behaviour of robbing a bank... to attain a state of wealth... may result in being re-directed into a state of imprisonment. In order to elevate your status, indulging in conspiratorial behaviour to displace the queen can get you either pregnant or headless or both. The pressure created by mass praying to prevent a volcanic eruption, is eventually released in a violent earthquake.

Any postulated ultimate state of 'happiness' is not easily attained nor recognized, and may well be an illusion, so that many behaviours aimed at attaining it are standard type I exercises in futility.