In the twentieth century, dating was sometimes seen as a precursor to marriage but it could also be considered as an end-in-itself, that is, an informal social activity akin to friendship.
This period of courtship is sometimes seen as a precursor to engagement.
From about 1700 a worldwide movement perhaps described as the "empowerment of the individual" took hold, leading towards greater emancipation of women and equality of individuals.
Men and women became more equal politically, financially, and socially in many nations.
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.