Men with more masculine digit ratios are partnered with more attractive women

Physical attractiveness predicts endorsement of specific evolutionary psychology principles

Evolutionary psychology has emerged as a controversial discipline, particularly with regard to its claims concerning the biological basis of sex differences in human mate preferences. Drawing on theories of motivated inference, we hypothesized that those who are most likely to be privileged by specific aspects of the theory would be most likely to support the theory. In particular, we predicted that physical attractiveness would be positively associated with endorsement of predictions of evolutionary psychology concerning mating strategies. Two studies confirmed this hypothesis. In Study 1, participants rated as higher in physical attractiveness were more likely to support specific principles of evolutionary psychology. In Study 2, a manipulation designed to boost self-perceived physical attractiveness increased endorsement of those same principles. Observer-rated physical attractiveness generally predicted individuals’ support of the theoretical principles better than did gender, political orientation, or self-esteem. Results suggest that those most likely to benefit according to certain predictions of evolutionary psychology are also those most likely to be sympathetic toward its relevant principles.

Assortative mating and digit ratio (2D:4D): A pre-registered empirical study and meta-analysis

BACKGROUND

It has been hypothesised that the ratio of length between the second and fourth fingers (2D:4D), commonly employed as an indicator of foetal sex hormone exposure, may be positively correlated between heterosexual partners.

AIMS

As previous evidence has been conflicting, our study aimed to determine whether intra-couple correlations exist for digit ratio variables, and if so, to estimate the size and direction of these effects.

STUDY DESIGN

We present a preregistered (osf.io/6jg8p) correlational study and quantitative meta-analysis of the available literature, and attempted to locate further published and unpublished data (i.e. 'grey literature') by contacting n = 248 researchers in the 2D:4D and related fields.

SUBJECTS

n = 58 heterosexual dating couples from the UK took part in our empirical study, and the meta-analysis included data from k = 11 samples.

OUTCOME MEASURES

We measured digit ratio for the right hand (R2D:4D), left hand (L2D:4D), and average of both hands (M2D:4D), as well as the right-left-difference (D_[R-L]).

RESULTS

We found no evidence of significant positive intra-couple correlations in our own data, but a significant (positive) meta-analytic effect size estimate emerged for R2D:4D (r = 0.072, p = 0.014). The meta-analytic effects for L2D:4D (r = 0.043, p = 0.303), M2D:4D (r = 0.070, p = 0.225), and D_[R-L] (r = 0.028, p = 0.649) were all in the same direction but not statistically significant. However, if the sample from Klimek et al. (2014, 2016) were omitted, meta-analysis would also yield a significant positive correlation for M2D:4D (r = 0.128, p = 0.001).

CONCLUSIONS

Although our findings are based on a fairly small range of studies, which themselves provide a relatively small sample of participants, they do imply the intriguing possibility of small effects of positive assortment in relation to characteristics associated with the prenatal hormonal environment.

Preference for Male Facial Masculinity as a Function of Mental Rotation Ability in Gay and Bisexual Men, but Not in Heterosexual Men and Women in China

This study examined the association between mental rotation ability and facial masculinity preference in gay and bisexual men in China. The participants (436 gay/bisexual men, 132 heterosexual men, and 254 heterosexual women) completed an online Shepard and Metzler-type mental rotation task and a forced-choice preference task of 10 pairs of masculinized/feminized male faces. The results revealed that mental rotation ability was significantly associated with preference for masculinized faces in both gay and bisexual men. There were no significant correlations between mental rotation ability and facial masculinity preference in both heterosexual men and women. The findings imply homogamy in partner preference in gay and bisexual men in terms of masculinity.