Researchers in many fields -- including animal behavior, anthropology, psychology, and sociology -- study social behavior. The term "social behavior" may be defined slightly differently depending on the field, but this definition (from biologist Terrence McGlynn) captures the main idea:
"Social behavior consists of a set of interactions among individuals of the same species."
This definition (from Biology Reference) is also helpful:
"Social behavior is defined as interactions among individuals, normally within the same species, that are usually beneficial to one or more of the individuals."
But it's important not to conflate "social behavior," which is neutral with respect to the nature of the social interactions, with terms like "prosocial behavior," which specify behavior that is intended to help others.
Social behavior can be friendly and mutualistic, as when two monkeys groom each other. Both parties receive immediate benefits.
It can be altruistic, as when a vampire bat donates food to a hungry companion. The donor pays a cost to deliver a benefit to the recipient.
But it can also be mutually antagonistic, as when two male elephant seals fight for access to females. And of course social behavior can include one-sided displays of aggression, or assertions of dominance.
Examples of human social behavior include:
- shaking hands
- religious rituals
- snubbing or "putting down" another person
- exchanging nonverbal signals (like smiles or frowns)
- offering reassurance or consolation
- sharing a meal
- disciplining a child
- singing or making music together
- any act of cooperation between individuals