Communities exerted pressure on people to form pair-bonds in places such as Europe; in China, society "demanded people get married before having a sexual relationship" and many societies found that some formally recognized bond between a man and a woman was the best way of rearing and educating children as well as helping to avoid conflicts and misunderstandings regarding competition for mates.
Generally, during much of recorded history of humans in civilization, and into the Middle Ages in Europe, weddings were seen as business arrangements between families, while romance was something that happened outside of marriage discreetly, such as covert meetings.
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.
The word "dating" entered the American language during the Roaring Twenties.
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.
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.