New types of relationships formed; it was possible for people to live together without marrying and without children.
It can be a form of courtship that consists of social activities done by the couple.
Behavior patterns are generally unwritten and constantly changing.
There are considerable differences between social and personal values.
Neurobiologist Robert Sapolsky constructed a reproductive spectrum with opposite poles being tournament species, in which males compete fiercely for reproductive privileges with females, and pair bond arrangements, in which a male and female will bond for life.
These species-particular behavior patterns provide a context for aspects of human reproduction, including dating.