Lower Digit Ratio (2D:4D) Indicative of Excess Prenatal Androgen Is Associated With Increased Sociability and Greater Social Capital

Abstract

Positive social interactions are crucial for human well-being. Elevated prenatal exposure to testosterone as indicated by a low second-to-fourth finger length ratio (2D:4D) relates to more aggressive/hostile behavior in men of low 2D:4D, especially in challenging situations. How much people enjoy interacting with others is determined by the personality trait sociability. Given its role in approach and avoidance behavior, sociability might also be influenced by prenatal sex hormones, but studies are inconclusive so far. Here, we investigated the association between 2D:4D and the personality trait sociability complemented by personal social capital and personal social network size, in a population-based cohort of 4998 men. Lower 2D:4D correlated significantly with higher trait sociability, bigger personal social capital, and larger personal social network size. These effects were consistent across both hands separately and their mean value. Furthermore, both factors of sociability (1) liking party and company of friends and (2) isolation intolerance, correlated significantly with the prenatal testosterone marker. The exploratory analysis revealed no link between 2D:4D and responses to the personality trait aggression items or items of anti-social-personality disorder. Our data suggest that prenatal androgen exposure organizes the brain with lasting effects on social behavior.

Molecular actions of sex hormones in the brain and their potential treatment use in anxiety disorders

“…Similar to animal studies, the effect of high prenatal T concentration on the increased risk for anxiety-like behavior in females, but not in male offspring ( 21 , 73 , 74 ) was observed in humans ( 103 , 104 ). In one recent study, daughters of mothers with PCOS had a 78% risk increase of anxiety disorders compared to daughters of mothers without PCOS, whereas no significant increase in risk was observed in sons ( 103 ).…”

“…In one recent study, daughters of mothers with PCOS had a 78% risk increase of anxiety disorders compared to daughters of mothers without PCOS, whereas no significant increase in risk was observed in sons ( 103 ). In men, a low 2D:4D ratio was significantly associated with higher trait sociability, bigger personal social capital, and a larger personal social network size rather than social anxiety disorders ( 104 ). Together, these data support a sex-dependent effect of high prenatal T exposure, which increases the risk for anxiety disorders, particularly in adult women.…”

Digit ratio (2D:4D) and transgender identity: new original data and a meta-analysis

“…This study investigated a possible association of 2D:4D and transsexuality in a large sample. It was part of the Finger Length in Psychiatry (FLIP) project 13 , 20 – 27 , a line of independent studies aiming to elucidate the role of prenatal sex hormone organization in the etiopathogenesis of psychiatric disorders in childhood, adolescence, and adulthood, such as addictive disorders 22 , 26 , 28 , 29 , 30 , suicide completion 31 , or behavioral symptoms in children 32 . Another goal was to establish prevention targets and strategies based on this model 33 .…”

Soccer Passing Accuracy Differentiates Between High and Low Digit Ratio (2D:4D) Soccer Players

“…The prenatal testosterone hormone calls the human mind and body an "organizational effect" before birth. The previous study reported, in men of low 2D:4D, elevated prenatal exposure to testosterone as indicated by a low digit ratio (2D:4D) refers to more aggressive/hostile behavior, especially in challenging situations [29]. Researchers Dyer et al, [30] found evidence that 2D:4D was a correlate of performance in an open skill sport in Basketball game.…”