Goals, Motivation And The Brain
The Greek philosopher Democritus (460-370 B.C.E.) might have been the first to hypothesize that the two fundamental human motives are to approach rewards and avoid pain. Several thousand years later, neuroscience has caught up by identifying some of the brain systems involved in approach and avoidance motivation.
Namely, greater left than right prefrontal cortical activation is linked to approach motivation, and, less often, greater right than left activation in these regions is linked to avoidance motivation.