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Updated: Aug 21, 2026

One Dimensional Turing-Like Handshake Test for Motor Intelligence
Published on: December 15, 2010
How well does second-to-fourth-digit ratio in hands correlate with other indications of masculinity in males?
Nicole Koehler1, Leigh W Simmons, Gillian Rhodes
1School of Psychology, The University of Western Australia, Crawley, WA 6009, Australia. nicole@psy.uwa.edu.au
Abstract:
Low second-to-fourth-digit (2D:4D) ratios in hands have previously been used as a proxy for prenatal testosterone levels. Moreover, it has recently been suggested that prenatal testosterone levels may direct future masculinization. If true, 2D:4D ratios should negatively correlate with traits in males that are developed and maintained by testosterone at puberty such as facial and body masculinity and testes volume. We failed to find significant correlations between 2D:4D ratios and these traits.
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