The 2nd to 4th digit ratio and developmental psychopathology in school-aged children

Sex steroids have important influences upon brain development and this may lead to sex differences in developmental psychopathology. Digit ratio (2D:4D) - a negative correlate of prenatal testosterone (T) - may provide further insight into the possible role of early organizational effects on such developmental psychopathology. We measured 2D:4D ratios in a group of schoolchildren in two countries (UK and Austria) and gave questionnaires assessing behavioural problems to their parents. Although there were few differences in behavioural measures between sexes (only the externalizing behaviour score was higher in Austrian boys), several correlations existed between 2D:4D and different indices of developmental psychopathology. Low 2D:4D (indicating higher prenatal T) was related to measures of total difficulties and poor conduct in both UK and Austrian children. In the UK sample, prosocial behaviour was positively related to 2D:4D in girls and hyperactivity and conduct correlated negatively with 2D:4D in boys. Associations were generally stronger for boys than for girls. We suggest that early androgen mediation effects during prenatal development increase the probability for gender-related behaviour problems.