Digit ratio (2D:4D), testosterone, cortisol, aggression, personality and hand-grip strength: Evidence for prenatal effects on strength

作者：Ribeiro Evaldo Jr; Neave Nick; Morais Rosana Nogueiro; Kilduff Liam; Taylor Suzan R; Butovskaya Marina; Fink Bernhard; Manning John T^*

来源：Early Human Development, 2016, 100: 21-25.

DOI：10.1016/j.earlhumdev.2016.04.003

• Digit ratio
• Testosterone
• Aggression
• Hand-grip strength

Background: Digit ratio (2D:4D) is a putative marker for prenatal testosterone and is correlated with performance in many sports. Low 2D:4D has been linked to strength but the evidence is mixed and strength is also influenced by mass, testosterone, and behavioural factors. It has been hypothesised that the 2D:4D-strength correlation may be strongest in challenge conditions when short-term changes occur in steroid hormones.
Aims: We tested this suggestion in men.
Study design: We used a cross-over study design with a challenge (an aggressive video of rugby tackles) and control (a blank screen) condition.
Subjects: 89 healthy men.
Outcome measures: Finger lengths (2nd and 4th for both hands), hand-grip strength (HGS), testosterone (T), cortisol (C), aggression (Buss-Perry Aggression Questionnaire) and personality type (Ten Item Personality Measure). In both conditions participants provided saliva samples (for hormone assays).
Results: In the challenge condition there was a highly significant increase in HGS, and modest changes in T, physical aggression and emotional stability. HGS correlated negatively with left hand 2D:4D. In a multiple regression, left hand 2D:4D was negatively related to HGS and emotional stability was positively related to HGS. In the control condition HGS was not correlated with 2D:4D. In a multiple regression, BMI, physical aggression, and emotional stability were significantly related to HGS.
Conclusions: 2D:4D is a negative correlate of strength in challenge situations. This finding may in part explain associations between 2D:4D and sports performance.

• 出版日期2016-9