@article{ref1,
title="Digit ratio (2D:4D), testosterone, cortisol, aggression, personality and hand-grip strength: evidence for prenatal effects on strength",
journal="Early human development",
year="2016",
author="Ribeiro, Evaldo and Neave, Nick and Morais, Rosana Nogueiro and Kilduff, Liam and Taylor, Suzan R. and Butovskaya, Marina and Fink, Bernhard and Manning, John T.",
volume="100",
number="",
pages="21-25",
abstract="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). <br><br>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. <br><br>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.<br><br>Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.<p /> <p>Language: en</p>",
language="en",
issn="0378-3782",
doi="10.1016/j.earlhumdev.2016.04.003",
url="http://dx.doi.org/10.1016/j.earlhumdev.2016.04.003"
}