Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations.

Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14-18, 19-30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry.

Are There Differences in Experts' and Lay Assessors' Attractiveness Judgments of Non-Professional Men's Dance/Gait Movements?

Research on attractiveness assessments of men's dance has shown that raters derive and integrate information about male mating-related qualities into their attractiveness assessments, but prior studies have focused on lay assessors (i.e., individuals with no professional dance background) rather than dance experts. We recruited male and female Russian dance experts (n = 23) to judge gender-neutral, featureless virtual characters, animated with motion-captured dance movements and gaits of British men, and compared their dance assessments to those from a group of Russian male and female lay assessors (n = 73). The dance experts provided higher dance and gait attractiveness judgments than the lay assessors. Both groups judged the gait movements to be of higher attractiveness than the dance movements. Differences in attractiveness assessments between experts and lay assessors were larger for the male judges than for the female judges. In an additional survey, the dance experts (versus lay assessors) placed greater emphasis on the importance of dance-related capacities and skills. We discuss our findings with reference to past research on dance/gait attractiveness as assessed by lay judges and the role of expertise in assessing body movement.