Having a partner who will be faithful is certainly one of the most desirable goals anyone can have in a long-term relationship. If only you could predict whether a current or prospective partner will fulfill this goal, how much simpler and happier your life would be. A new study by Jaako Aspara and colleagues (2018), of the Hanken School of Economics (Finland), suggests that when it comes to picking a male partner, the smarter one is the better bet.
Aspara et al. write from an evolutionary perspective as the background to their study, and although this perspective can be criticized (as I will get to later), it's important to explain their rationale. The authors note that intelligence could have direct effects on the “fitness” of marital partners to “survive and support the offspring," but also indirect effects via the ability of smarter men to make larger incomes. If you follow this logic, it’s a man’s intellectual potential that creates the evolutionary imperative. Men need the greater intelligence to be able to attract women who will want to have their children. Furthermore, the higher intellect of a smart man should also make him more desirable as someone to stick with, argue the authors, due to his greater “fitness.”
Aspara and colleagues were able to draw from the vast repository of military conscription data from nearly 200,000 Finnish men in the age range of 18 to 45 years old. The measure of intelligence consisted of a 120-item test administered as they entered the Finnish Defense Forces. At the time of their initial assessment, approximately two-thirds were single. They were matched for their age and region of residence with married men, and all were followed up with for five years, during which time their marital status at both points was obtained from official government records. Other variables of interest in indexing social class included income, language group, commuting costs, age, and residence in the capital city. Additionally, the authors used car possession as a tangible status indicator, both in terms of size and in terms of model year, with larger and newer cars having higher status. The intelligence test included scales measuring numerical, verbal, and nonverbal abilities. A large majority (70 percent) of the available population completed this test.
The findings showed that intelligence and marital history were indeed related. Within each of the five age groups used to classify the men in the study up to those in the 41 to 45-year-old group, the proportion of men getting and staying married rose with each increase in overall intelligence. More fine-grained analyses compared the type of intellectual ability and the impact of age and social status, as measured by income and that all-important automobile.
Perhaps because marital histories tend to fluctuate more before the age of 45, the impact of intelligence for the men in this study was more pronounced in the younger groups. The probability of getting married was particularly strongly related to verbal intelligence, and all three components of intellectual ability were related equally to the probability of getting divorced. Although men with newer and larger cars were also advantaged in the marital equation, the impact of intelligence remained significant after these effects were statistically controlled.
It would appear, then, that verbal intelligence does relate to a younger man’s ability to attract a partner, and overall intelligence to the ability to avoid breaking up with a partner. However, it’s important to keep in mind that with scores from nearly an entire population, small differences take on statistical significance rather easily. The probability of getting married within six years of the first testing for those high in verbal intelligence was .17, while the less intellectually advantaged had a .11 probability of finding a marital partner. Similarly, the probability of staying married ranged at the low end from .91 to just .93 at the upper end of the overall intelligence scale. The possession of a large, new car, which had a higher relationship to marital history than intelligence, still was fairly small in its absolute effect.
Women do seem to want smarter men, but they also want men with nice cars. To the extent that the results support the advantage of high intelligence (especially verbal) to long-term relationships, one might still wonder about the conclusion made by the authors that “In parallel to the effect of a peacock’s mysterious tail on its mating success…human intelligence has a direct positive impact on human mating prospects in terms of marriage." Rather than “resolve the previous uncertainty in evolutionary theory," might the findings speak to the idea of intelligence and overall relationship quality? Men who are smarter, particularly those who can express themselves, might be better able to discuss their feelings in a more comprehensible manner, both when forming and maintaining relationships. Further, the authors maintain that intelligence has a stronger mating cachet for younger women, who are more “demanding of their partners’ resource and fitness indicators." Again, though, might the findings suggest that the more verbally intelligent men are just that much more articulate and mature?
You might now be wondering about the nature of the women who are judging the intellectual fitness of their partners or potential partners. If we believe that, all other things being equal, women prefer brighter men, the other piece of the puzzle is whether those brighter men find their partners to be scintillating enough to get them through the long haul. Are they able to have intellectually stimulating conversations, particularly after the early flush of romantic attraction passes by? (It's worth noting that women who are highly intelligent themselves have been found to enjoy more stable and enduring marriages.) Also, since this was a correlational study, we don't know if the smarter men are more desirable to women, or if the smarter men are more likely to want long-term relationships.
To sum up, evolutionary questions aside, the Finnish study supports those investigations linking aspects of intelligence to some measures of life success, including the research showing that people who are high in intelligence not only can, but do, have very successful relationships. Whether or not people are like peacocks, it would seem that developing those qualities which allow you to talk to your partner can help give your relationship a solid communicative foundation.
Aspara, J., Wittkowski, K., & Luo, X. (2018). Types of intelligence predict likelihood to get married and stay married: Large-scale empirical evidence for evolutionary theory. Personality and Individual Differences, 1221-6. doi:10.1016/j.paid.2017.09.028