Past research has determined that humor plays a role in selecting a mate, but the exact evolutionary function has yet to be determined. There are three common theories. The first suggests that humor functions as an indicator for genetic quality. Humor requires intelligence and verbal skills, both of which display psychological fitness. The second theory states that humor is an interest indicator. If the recipient responds with genuine laughter or interest, then the humor producer will believe the recipient is interested in a relationship. Finally, the third theory believes that humor is a way of showing compatibility. Jokes require background knowledge, attitudes, and values. Couples with a similar sense of humor tend to stay together.

The current study published in Evolutionary Psychology recruited 116 undergraduate students as participants. They were shown 24 facial photographs of opposite sex individuals who were either higher or lower in attractiveness, and then information about said individual’s humor receptivity and productivity. The participants then ranked their desire for a short term and long term relationship, as well as physical attractiveness.

For long term relationships, the results revealed that both humor production and receptivity were important for both men and women. However, humor production had a greater effect on women’s rating than it did for men. This finding fits in with the psychological fitness view, as men must display humor, showing off their intelligence and verbal skills. Receptivity was also a strong factor for women for long term partners, which goes against the psychological fitness theory. Instead, this supports the idea that humor may be a way to convey compatibility. If a man is not receptive to his partner’s humor, it may show that he does not share the same values with her.

For short term relationships, the effects of physical attractiveness were more important than in long term relationships. However, in regards to humor, there were no sex differences. Overall, the effects of humor were more pronounced for long term partners than short term partners. These findings were inconsistent with the three theories discussed above. Both high humor production and high humor receptivity boosted the attractiveness of a partner.

The researchers commented that both the psychological fitness model the compatibility model were best displayed with the results. Humor is able to convey compatibility in terms of shared goals, values, and background knowledge; humor may also serve as an indicator of romantic interest. An interesting limitation is that this study used only heterosexual males and females, and a follow-up using homosexual participants may yield different results.