However, one particularity of the human species is that pair bonds are often formed without necessarily having the intention of reproduction.
In modern times, emphasis on the institution of marriage, generally described as a male-female bond, has obscured pair bonds formed by same-sex and transgender couples, and that many heterosexual couples also bond for life without offspring, or that often pairs that do have offspring separate.
Social rules regarding dating vary considerably according to variables such as country, social class, race, religion, age, sexual orientation and gender.
Behavior patterns are generally unwritten and constantly changing.
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.