Associations between digit ratio (2D4D), mood, and autonomic stress response in healthy men

Abstract

The ratio between the length of the second (index) and the fourth (ring) finger (2D4D) is a putative biomarker of prenatal testosterone (T) exposure, with higher exposure leading to a smaller ratio. 2D4D has further been linked to mental and somatic disorders. Healthy male Swiss recruits (N = 245; Mage = 20.30 years) underwent a psychosocial stress test. Mood and salivary alpha‐amylase (sAA) were assessed before and after the stress test, while heart rate (HR) and heart rate variability (HRV) were measured continuously. Additionally, 2D4D (right: R2D4D; left: L2D4D) was determined and divided into quartile groups. Correlation analysis showed no associations between R/L2D4D and outcome measures. Comparing calculated quartiles for R2D4D, subjects in the lowest R2D4D quartile expressed trendwise (p < 0.10) lower positive and higher negative affect, significantly elevated sAA activity (p < 0.05), but no HR and HRV differences at baseline as compared to subjects in the upper three quartiles. With regard to acute stress, subjects in the lowest as compared to subjects in the upper three R2D4D quartiles showed a higher increase of negative affect and a stronger cardiac response (p < 0.05), but no alterations in positive affect and sAA activity. Young healthy men in the lowest R2D4D quartile revealed a more negative affect and increased physiological activity at baseline and in response to acute stress. An exposure to high levels of prenatal T might constitute a risk factor potentially increasing vulnerability to stress‐related disorders in men.

Resilience as a Protective Factor in Basic Military Training, a Longitudinal Study of the Swiss Armed Forces

“…The study was conducted during autumn 2011 and spring 2012. The present analysis was part of a broader study of biological and psychological characteristics of recruits to the Swiss Armed Forces [ 28 , 61 , 62 , 63 , 64 , 65 ]. However, the present results have not previously been published and therefore are novel.…”

Transformational Leadership, Achievement Motivation, and Perceived Stress in Basic Military Training: A Longitudinal Study of Swiss Armed Forces

“…The present analysis was part of a larger study of biological and psychological characteristics of recruits to the Swiss Armed Forces [50,51,56,[60][61][62]. Data have not previously been published or presented in this form.…”

Depression, neuroticism and 2D:4D ratio: evidence from a large, representative sample

“…However, the research so far has not yielded conclusive results. In the case of depression, some studies reported null results [39][40][41][42][43][44] , while others found significant positive as well as significant negative associations with 2D:4D. Moreover, all significant results were restricted to either female or male participant groups, with no study reporting a significant relationship between depression and 2D:4D in both sex groups: There was one significant positive 45 and one significant negative 46 association in females, as well as two significant positive 47,48 and two significant negative 49,50 associations in males.…”