Sublime

So Dunbar proposed a novel idea: the size of a species’ brain determines the optimal size of their social groups. Maintaining relationships, argued Dunbar, requires brain power. More relationships require more neurons. Extrapolating his straight line from primate brains to human brains, he found that the optimal human group size, if this hypothesis

Teasing apart the motives for what psychologists call “socially desirable responding” can be a challenge.

In 2010, researchers at the University of Amsterdam found that the effects of oxytocin seem limited to one’s own group.2 The hormone not only enhances affection for friends, it can also intensify aversion to strangers. Turns out oxytocin doesn’t fuel universal fraternity. It powers feelings of ‘my people first’.

Jeffrey Hall,

Peer pressure, or the desire to be part of the in-group, is a second source of social influence.

being able to see who else has taken a class or what their level of participation was can influence the behavior of subsequent students.

located two Facebook datasets, one small and one large (and, no, they didn’t get either of them from Cambridge Analytica . . . both are publicly available), and downloaded a large sample of Twitter traffic (if you know how to do this, it is easy to do and, because Twitter is publicly accessible, it is perfectly legal).

Beliefs, practices, technologies, and social norms—culture—can shape our brains, biology, and psychology, including our motivations, mental abilities, and decision-making biases.