The effects of prenatal testosterone on wages: Evidence from Russia

Relationship between the 2D:4D and prenatal testosterone, adult level testosterone, and testosterone change: Meta-analysis of 54 studies

The ratio between the hands' second to the fourth finger (2D:4D) is commonly hypothesized to result from prenatal testosterone. The 2D:4D has also been hypothesized to relate to adult-level testosterone and, more recently, to the testosterone response to a challenging situation. In the present work, we tested these core assumptions. Drawing from, in total, 54 studies and 8077 participants, we investigated whether the 2D:4D is related to adult level testosterone (44 studies), testosterone change (6 studies), and prenatal testosterone (10 studies). We found no evidence of the relationship between the above testosterone types and digit ratios. Furthermore, there was no relationship between testosterone and the right and left 2D:4D, male and female 2D:4D, and the 2D:4D and testosterone measurement (i.e., measured in blood or saliva). However, we found some evidence that prenatal testosterone measured in amniotic fluid (but not cord blood) might be related to the digit ratios-further studies are necessary to validate this observation. In summary, considering the current state of knowledge, any conclusions drawn from the assumption of the digit ratios as the proxy for testosterone (prenatal, adult level, or testosterone change under a challenging situation) warrant great caution.

Born to be wild: Second-to-fourth digit length ratio and risk preferences

The second-to-fourth digit length ratio of an individual's hand (digit ratio) is a putative biomarker for prenatal exposure to testosterone. We examine the hypothesized negative association between the digit ratio and the preference for risk taking within a large U.S. population survey. Our statistical framework provides a cardinal proxy for the true digit ratio based on ordinal digit ratio measurements and accounts for measurement error under the assumptions of Gaussianity and time-invariant true digit ratios. Our empirical findings support the hypothesis and suggest a meaningful biological basis for risk preferences.

In and out of unemployment-Labour market transitions and the role of testosterone

Biological processes have provided new insights into diverging labour market trajectories. This paper uses population variation in testosterone levels to explain transition probabilities into and out of unemployment. We examine labour market transitions for 2004 initially employed and 111 initially unemployed British men from the UK Household Longitudinal Study ("Understanding Society") between 2011 and 2013. We address the endogeneity of testosterone levels by using genetic variation as instrumental variables (Mendelian Randomization). We find that for both initially unemployed men as well as initially employed men, higher testosterone levels reduce the risk of unemployment. Based on previous studies and descriptive evidence, we argue that these effects are likely driven by differences in cognitive and non-cognitive skills as well as job search behaviour of men with higher testosterone levels. Our findings suggest that latent biological processes can affect job search behaviour and labour market outcomes without necessarily relating to illness and disability.

Testosterone and socioeconomic position: Mendelian randomization in 306,248 men and women in UK Biobank

Men with more advantaged socioeconomic position (SEP) have been observed to have higher levels of testosterone. It is unclear whether these associations arise because testosterone has a causal impact on SEP. In 306,248 participants of UK Biobank, we performed sex-stratified genome-wide association analysis to identify genetic variants associated with testosterone. Using the identified variants, we performed Mendelian randomization analysis of the influence of testosterone on socioeconomic position, including income, employment status, neighborhood-level deprivation, and educational qualifications; on health, including self-rated health and body mass index; and on risk-taking behavior. We found little evidence that testosterone affected socioeconomic position, health, or risk-taking. Our results therefore suggest that it is unlikely that testosterone meaningfully affects these outcomes in men or women. Differences between Mendelian randomization and multivariable-adjusted estimates suggest that previously reported associations with socioeconomic position and health may be due to residual confounding or reverse causation.

The 2D:4D ratio does not always correlate with economic behavior: A field experiment with African-Americans

Several studies present evidence of correlations between prenatal testosterone exposure measured with the 2D:4D ratio and behaviors such as pro-social behavior, risk and patient attitudes, and self-employment. Individuals exposed prenatally to higher levels of testosterone have lower levels of risk aversion, higher levels of patience and invest more in others, and in themselves, therefore have higher individual financial wellbeing. We test these hypotheses with a sample of 115 African-Americans who live in a low-income urban area in the U.S. The 2D:4D ratio in our sample of males and females does not have a consistent and robust correlation with risk, patient attitudes, pro-social behavior and self-employment in contrast to previous studies.