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.
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.
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.
It generally happened in that portion of a person's life before the age of marriage, enabled dates to be arranged without face-to-face contact.
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.
With the use of modern technology, people can date via telephone or computer or meet in person.
Dating may also involve two or more people who have already decided that they share romantic or sexual feelings toward each other.
Cars extended the range of dating as well as enabled back-seat sexual exploration.