In 1957, thousands of female high school seniors in Wisconsin took their senior yearbook photos, not knowing how those photos would be used. How could they know that the way they looked in that photo would be used in a 2018 study to predict how smart their future husbands turned out to be? That study, published in Evolutionary Behavioral Sciences, shows the consequences of class photo day: Attractive women tended to have intelligent husbands.
“We speculate that women are motivated to secure a mate with equal or higher intelligence,” write the team of male authors behind the study.
Specifically, the study shows that women who were judged as attractive in their black-and-white 1957 yearbook photo ended up having husbands who scored higher on IQ tests taken around the same time, at least according to the study. This astounding finding, which supports one evolutionary psychology theory about the differing mate preferences between women and men, was based on an analysis of data from the Wisconsin Longitudinal Study (WLS), a survey of over 10,000 Wisconsin high school seniors that began in 1957 that assessed IQ, among other characteristics.
There are, perhaps unsurprisingly, some significant caveats to consider about this study.
Perhaps most suspicious is that the IQ scores for both the participants and their eventual spouses were determined in the 1950s, but the “attractiveness” scores came from 2004, when an independent cohort of six men and six women rated how attractive each participant’s 1957 yearbook photo was on a scale of one to 11. The average age of the people asked to rate attractiveness in 2004 was 78.5, roughly the current age of the people whose high school photos they were rating.
By comparing those values, the study’s authors found that more attractive women had a slight tendency to marry men with higher IQs. They also found that the opposite was not true: Male attractiveness did not predict the IQ score of their future wives.
These conclusions may seem contradictory, but they are exactly what the team of researchers, led by Western Illinois University professor of psychology Curtis S. Dunkel, Ph.D., expected to find because they based their analysis on an idea in evolutionary psychology called “sexual strategies theory.”
Sexual Strategies Theory
Coined in a 1993 paper by David Buss, Ph.D., a professor at the University of Texas at Austin, sexual strategies theory has one foot in traditional evolutionary theory and one foot in sexual selection. It uses both to explain why men and women appear to have different priorities when it comes to dating.
The theory is based on one assumption: When it comes to mating, men and women need different things. A woman, who has to carry a child for nine months, has to consider the long-term implications of choosing a mate. Therefore, she desires traits that demonstrate long-term “fitness” — like intelligence. Men, on the other hand, have less to lose when it comes to choosing a mate, so they can value short-term fitness values, like attractiveness.
Sexual strategy theory suggests that, given the difference in their demands, men and women have adopted different strategies to ensure they get what they want out of a partner. In his textbook Evolutionary Theories in Psychology, Buss explains:
Modern women have inherited the evolutionary trait to desire mates who possess resources, have qualities linked with acquiring resources (e.g., ambition, wealth, industriousness), and are willing to share those resources with them. On the other hand, men more strongly desire youth and health in women, as both are cues to fertility.
The authors of the current study cite sexual strategy theory as a foundation for their hypothesis. When they investigated the idea that a woman’s 1957 yearbook photo could reveal something about her husband’s IQ, they were looking to see whether the proposed idea that women seek out long-term fitness traits, like intelligence, played out in this sample. In this analysis, it did, and Dunkel referred to some tenets of sexual strategies theory when he described his findings to PsyPost.
“The results of the study suggest that intelligence may be slightly more important to women when choosing a long-term mate,” Dunkel said. “More specifically, a woman may look for a man who is slightly more intelligent than she is and she uses her physical attractiveness to secure a more intelligent husband.”
In both the conclusion of this paper, as well as Buss’s explanation of sexual strategies theory, these researchers add that there will obviously be caveats to their interpretations. There are plenty of women who raise children on their own, and there are obviously plenty of men who seek out intelligent women. The researchers also weren’t able, Dunkel added, to test a number of different hypotheses that might undercut these findings. So while the conclusions of this study may ring true in some people, the science behind this effect is still very much in its infancy.