Why we follow social norms decoded

Humans follow social norms to forge co-operation among peers, even though such unspoken rules of the society sometimes require them to make personal sacrifices, scientists say.
Social norms - unspoken rules of how we dress, talk, eat and even allow ourselves to feel - are often internalised to such a degree that we probably do not even notice them.
Following norms, however, can sometimes be costly for people if norms require sacrifice for the good of the group.
Researchers from the University of Tennessee in the US wanted to delve into why humans evolved to follow such norms in the first place.

The results, published in the Proceedings of the National Academy of Sciences, show that the ability of humans to internalise social norms is expected to evolve under a wide range of conditions, helping to forge a kind of cooperation that becomes instinctive.
Researchers used computer simulations to model individual behaviour in group actions and underlying genetic machinery controlling such behaviour.

They worked from the premise that adherence to norms is socially reinforced by the approval of, and rewards to, individuals who follow them and by punishment of norm violators.
In the model, individuals make choices about participating in collective actions that require cooperation, and individuals who do not cooperate, or "free riders," can face consequences.

The model shows that encouraging peer punishment of free-riders is much more efficient in promulgating cooperation in collective actions than promoting participation itself.
The study predicts a significant genetic variation in the ability of humans to internalise norms.
Under some conditions populations are expected to have a relatively small frequency of "over-socialised" individuals who are willing to make extreme sacrifices for their groups.
Examples in today's society might be suicide bombers and other displays of extreme self-sacrificial behaviour for the perceived good of the group, researchers said.
Likewise, there are also "under-socialised" individuals - psychopaths - who are completely immune to any social norms.

"Every day human beings make choices among multiple options in how to respond to various social situations. Those choices are affected by many interacting factors, including social norms and values," said Sergey Gavrilets, a professor at the University of Tennessee.
"Understanding the effects of social norms could help us better understand human decision-making and better predict human actions in response to certain events or policies," Gavrilets.
Gavrilets also said the models could be helpful in social and economic policymaking.
"Generalising our models can lead to the development of better tools for predicting consequences of introducing certain social policies and institutions and in identifying the most efficient strategies for changing or optimising group behaviours," he said.