Digit ratio (2D:4D) and its behavioral correlates in infant rhesus macaques (Macaca mulatta). Issue 7 (12th September 2019)

• Record Type: Journal Article
• Authors: Paukner, Annika
• Other Names: Bales Karen guestEditor.; Brumley Michele guestEditor.
• Is Part Of: Developmental psychobiology. Volume 62:Issue 7(2020)
• Page Start: 992
• Page End: 998
• Publication Date: 2019-09-12
• Subjects: aggression -- digit ratio -- infant -- play -- sex differences; Psychobiology -- Periodicals; 155
• DOI: 10.1002/dev.21917
• Languages: English
• ISSNs: 0012-1630

Abstract

Abstract: 2D:4D ratios are typically lower in adult human males than females and are linked to numerous sex‐differentiated behaviors. 2D:4D ratios are considered an indicator of prenatal androgen exposure; if so, children's 2D:4D ratios would arguably be even better indicators of prenatal androgen exposure since children have experienced fewer postnatal influences than adults. However, sex differences in 2D:4D ratios as well as associations between 2D:4D ratios and sex‐typed behaviors in children have been inconsistent. Several studies also report sex differences and behavioral correlates of 2D:4D ratios in adult non‐human primates, but little is known about 2D:4D ratios in infant non‐human primates. This study examined sex differences in 2D:4D ratios over the first month of life, and associations with behavioral outcomes at 12–24 weeks of age, in N = 304 infant rhesus macaques. An increase in 2D:4D ratios over the first month of life was found, as well as associations with aggression and play behaviors, but no sex differences in 2D:4D ratios were observed. These results highlight the need for future developmental studies of 2D:4D ratios in order to determine not only their stability and predictive value, but also to discern the mechanism connecting prenatal androgen exposure, 2D:4D ratios, and behavioral outcomes.