Those age preferences consistently hover around the values denoted by the rule (the black line).

21 year olds online dating-3821 year olds online dating-11

This rules states that by dividing your own age by two and then adding seven you can find the age boundary: Take your age, subtract 7, and double it.

So for a 24-year old, the upper age limit would be 34 (i.e., 17 * 2).

According to the rule, for example, a 30-year-old should be with a partner who is at least 22, while a 50-year-old’s dating partner must be at least 32 to not attract (presumed) social sanction. Does it match our scientific understanding of age-related preferences for dating? Researchers Buunk and colleagues (2000) asked men and women to identify the ages they would consider when evaluating someone for relationships of different levels of involvement.

People reported distinct age preferences for marriage; a serious relationship; falling in love; casual sex; and sexual fantasies. Based on the figures Buunk and colleagues (2000) provided (and thus the numbers are only informed approximations), I replotted their data superimposing the max and min age ranges defined by the half-your-age-plus-7 rule.

For example, this sample of 60-year-old men report that it is acceptable to fantasize about women in their 20s, which the rule would say is unacceptable.

With some quick math, the rule provides a minimum and maximum partner age based on your actual age that, if you choose to follow it, you can use to guide your dating decisions.

The utility of this equation is that it lets you chart acceptable age discrepancies that adjust over the years. Let's examine it: How well does the rule reflect scientific evidence for age preferences?

In Figure 1, the solid black line represents the rule’s calculation for minimum acceptable range.

You can see that men are basically operating by the rule for minimum age preferences for marital relationships (blue bars) and serious dating relationships (yellow bars).