In sociometry, small groups made up of individuals who choose one another are called

In sociometry, small groups of individuals who mutually choose one another are called cliques.

Stars are individuals who receive many choices, not the mutually-choosing subgroup.

Isolates are individuals whom no one chooses.

Pairs, or dyads, involve only two mutually choosing persons, not a small group.

A clique appears in a sociogram as a cluster of reciprocated links.

Sociometry was developed by J. L. Moreno to map interpersonal choices within groups.