Format

Send to

Choose Destination
Early Hum Dev. 2016 Sep;100:21-5. doi: 10.1016/j.earlhumdev.2016.04.003. Epub 2016 Jul 6.

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

Author information

1
Department of Physiology, University of Paraná, Curitiba, Brazil.
2
Department of Psychology, Northumbria University, Newcastle-upon-Tyne, UK.
3
Applied Sports, Technology, Exercise and Medicine (A-STEM), Swansea University, Swansea, UK.
4
Sport and Exercise Sciences, Glyndwr University, Wrexham, UK.
5
Department of Cross-Cultural Psychology and Human Ethology, Institute of Ethnology and Anthropology, Russian Academy of Sciences and Russian State University of Humanities, Moscow, Russia.
6
Institute of Psychology, University of Göttingen, Göttingen, Germany.
7
Applied Sports, Technology, Exercise and Medicine (A-STEM), Swansea University, Swansea, UK. Electronic address: j.manning@swansea.ac.uk.

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).

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.

KEYWORDS:

Aggression; Digit ratio; Hand-grip strength; Testosterone

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center