Happiness as a signal of good fit with human nature

What indicates a good fit with the nature of an organism? One sign is the continuation of the species. This may involve high birth rates — as Will notes — but not necessarily so. Another sign is physical thriving as apparent in rising longevity and increasing body size. In organisms with the ability to makes choices there is still another marker: how well they feel. Affect typically informs choosing organisms about whether they are in the right pond or not; they tend to feel good in habitats that fit their repertoire of adaptations and tend to feel bad in environments that do not. In higher animals, affective experience also hints at the appropriateness of some behaviors, such as mate selection. This affective orientation system exists in all mammals and serves to ensure the gratification of “needs” of which the organism is typically unaware. Like every system, it is not flawless.