Trust me, I’m a scientist
Although we do fall out occasionally, human society is notable for its degree of cooperation between individuals
Cooperation presents a difficulty for evolutionary theory, which at its simplest suggests that individuals should just look out for themselves. Research suggests that there is a genetic component underlying this phenomenon, in which even less-closely related individuals help each other.
More sophisticated analyses, though, show that helping others can bring you benefits – the phenomenon of indirect reciprocity: you help somebody, somebody else helps you. This analysis can explain how factors such as reputation, perceived moral character and other aspects of social communication can develop.
We know a little about the brain systems responsible for these phenomena. Logical reasoning plays a part but is not the whole story. One interesting player is the hormone oxytocin, which encourages bonding. When given to subjects playing a risky investment game, it makes them more trusting of their (unidentified) partners.Lead image:
The US Food and Drug Administration/Flickr CC BY