It lets you chart acceptable age discrepancies that adjust over the years. According to the rule, for example, a 30-year-old should be with a partner who is at least 22, while a 50-year-olds dating partner must be at least 32 to not attract (presumed) social sanction.

What is considered a big age gap in a relationship?

Heterosexual couples tend to have about a three-year age difference, research suggests. Evolutionary psychology explains why men are usually older in heterosexual age-gap relationships.