Norwegian Men and Women Value Similar Mate Traits in Short-Term Relationships. Mehmet Mehmetoglu, Ilmari Määttänen. Evolutionary Psychology, December 29, 2020. https://doi.org/10.1177/1474704920979623
Rolf Degen's take: https://twitter.com/DegenRolf/status/1343866293712261121
Abstract: Previous research has provided evidence that females are generally the more selective sex in humans. Moreover, both sexes have been found to be more selective in long-term mating compared to short-term mating. In this study, we have examined the effects of sex, mating strategy (preferred relationship length) and their interaction on mate preferences (i.e., mate selection criteria) in an egalitarian Nordic society, namely Norway. The study sample consisted of 1,000 individuals, 417 of whom were male and 583 female respondents. According to our findings, men were more selective in physical appearance, whereas women were more selective in all the other mate preferences (e.g., understanding, dominant, kind, intellectual etc.). The respondents that were seeking short-term relationships had higher preference for physical appearance, humorousness and sociability. On the other hand, the respondents that were seeking long-term relationships were more selective in most of the other mate preferences (i.e., understanding, kind, cultivated, domestic, reliable, and similar). Interestingly, no interaction effect was found between sex and mating strategy in that differences between long-term and short-term seekers in mate preferences did not change depending on sex. This suggests that men and women value the same traits in short-term relationships.
Keywords: mate preference, sex differences, sexual selection, long-term mating, short-term mating
To recap, we found evidence for sex differences in mate selection criteria: men were more selective with respect to physical attractiveness and women were more selective with respect to all the other mate preference criteria. This was an expected result in light of previous research with similar findings (Buss & Schmitt, 1993; Castro & Lopes, 2011; Regan et al., 2000; Shackelford et al., 2005). The respondents that were searching for a short-term partner had a higher preference for physical attractiveness, humorousness and sociability. The respondents that were searching for long-term relationships were more selective in most of the other mate preference criteria. Perhaps surprisingly, no interaction effect between mating strategy and sex was found. This was contrary to what was predicted, based on Sexual Strategies Theory.
The respondents that were searching for long-term relationships were more selective in most of the other mate preference criteria (see also Castro &Lopes, 2011; Stewart et al., 2000). An issue with previous studies on the topic of short/long term relationship and sex differences is that typically the groups have been analyzed separately while often implying that there is an interaction between the sex and relationship length.
The results also suggested sex differences in preferences depending on the relationship length, but a relationship duration-sex interaction was not explicitly presented (Stewart et al., 2000). Thus, it is not completely clear, whether relationship length and sex interact with each other when they are analyzed together in a single analysis. This is a major question when resolving the hypotheses around this issue.
So, does each sex have also their particular preference when it comes to short-term mating (compared to long-term mating), or do both sexes have the same predictable pattern of preferences? Direct evidence for such an interaction-effect is relatively scarce in general. One exception was a study, in which sex and relationship length had an interaction in which women displayed a higher preference for partner’s sexual passion and desire for short-term partner than long-term partner, whereas there was no such difference among men (Regan et al., 2000). Another study found a sex-relationship length interaction in which both sexes had a similar high preference for attractiveness in short-term relationships but not in long-term relationships, in which women did not pay as much attention to attractiveness (Li & Kenrick, 2006). At least one study found no relationship length-sex interaction and interpreted this as evidence against Sexual Strategies Theory and in favor of Attachment Fertility Theory (Pedersen et al., 2014). Similarly, our results did not support such interaction effect, and thus underlying sex difference in any of the preferences.
One issue that may make interpreting the results more difficult may be the reporting style and underlying choosiness of each sex. For instance, commonly found self-reported preference for physical attractiveness may be influenced by different perception of attraction among different sexes: it is possible that women are more critical in their evaluations.
This study was conducted in an egalitarian, Nordic society, which may be relevant in the study of sex differences in preferences, as they are influenced by social change and societal norms (Bech-Sørensen & Pollet, 2016). Gender equality and strong social safety nets provided by the government may unmask preferences, which might in other environments be hidden under the most urgent materialistic needs. Chinese women, especially those with high socioeconomic status or who lived in cities, preferred “good father” over “good genes” or “good provider” in a self-report study (Lu et al., 2015). Some studies have provided evidence of change in preferences over time (Souza et al., 2016). Studies utilizing personality traits have provided evidence that people prefer traits that are associated to their own traits even in more traditionalistic societies such as Islamic countries (Atari et al., 2020).
Our results lacked the hypothesized interaction-effect, and thus did not support Sexual Strategies Theory, but it is not clear whether or not the results can be interpreted as supporting Attachment Fertility Theory (Pedersen et al., 2014) or some other existing theory. It is also worth remembering that not all traits are adaptations. Some features or traits may be a result of selection for that trait in the other sex (e.g., male nipples) or may otherwise be byproducts of an adaptation (Gould & Lewontin, 1978). It is possible that a similar issue may arise with preferences that are interpreted to be sex-specific or not sex-specific. As an example, it is possible that short-term mate preferences are actually adaptations in men but not in women.
Several studies have studied long- and short-term mating preferences via several different research methods, often in conflicting choice-situation (see Conroy-Beam & Buss, 2019; Cottrell et al., 2007; Mogilski et al., 2019; Perilloux & Cloud, 2019). As their experimental designs and methods differ from the current study, their use as a comparison against the results for this study is not completely straight-forward.
There were some limitations in the sample. The data was self-reported. However, self-reported preference measures are the most commonly used method in other studies of human mate preferences as well. It is also possible that people who are seeking a short-term relationship differ in their attractiveness from the ones who are seeking a long-term relationship. This, in turn, might have an influence on the preferences of the individuals. One final limitation of the study is that for interactions statistical power depends on the number of observations in the smallest cell, which in our case, corresponds to women respondents seeking short-term relationship (n = 63). There were 520 women respondents seeking long-term relationship, 92 men respondents seeking short-term relationship, and 325 men respondents seeking long-term relationship. The number of women seeking short-term relationship was low, as such, power to detect interactions if they exist was low, thus, the non-significant interactions should be interpreted cautiously. Future studies should pay attention the interaction-result that we presented in this study. In ideal case, a large number of women seeking for short-term relationships should be recruited for the study. Perhaps some innovative experimental design could also study this issue in the future.