This is called contact theory where intergroup contact reduces intergroup prejudice.

这就是所谓的接触理论，群体间的接触减少了群体间的偏见。

Larger homogenous groups tend to turn inward, concentrating relationships within the group instead of relying on intergroup contacts.

较大的同质群体倾向于向内转，集中在群体内部的关系，而不是依赖群体间的联系。