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.
New types of relationships formed; it was possible for people to live together without marrying and without children.
Information about human sexuality grew, and with it an acceptance of all types of sexual orientations is becoming more common.
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.
With the use of modern technology, people can date via telephone or computer or meet in person.