Motivation and Decision-Making

Abstract

It is a matter of common observation that an animal does not respond to a stimulus in the same way every time that stimulus is encountered. We only have to think of the lion moving through the bush and coming upon a herd of wildebeest. On some occasions such an encounter results in the lion stalking and perhaps killing one of the wildebeest. On others, the lion walks casually past apparently ignoring the presence of potential food. A male chaffinch, during winter, vigorously defends his territory against conspeciflc intruders of either sex. In spring, however, he selectively admits and courts females while continuing to drive off other males. Something about the lion and the chaffinch in these two examples has changed between, one encounter with food or a female and another. But what has changed? Since there is no difference in the stimulus itself, we are left with the possibility of some internal change in the animal. That internal change we can conveniently label motivation.