Season of birth and handedness in Serbian high school students

Abstract

BackgroundAlthough behavioural dominance of the right hand in humans is likely to be under genetic control, departures from this population norm, i.e. left- or non-right-handedness, are believed to be influenced by environmental factors. Among many such environmental factors including, for example, low birth weight, testosterone level, and maternal age at birth, season of birth has occasionally been investigated. The overall empirical evidence for the season of birth effect is mixed.MethodsWe have investigated the effect of season of birth in an epidemiologically robust sample of randomly selected young people (n = 977), all born in the same year. A Kolmogorov-Smirnov type statistical test was used to determine season of birth.ResultsNeither the right-handed nor the non-right-handed groups demonstrated birth asymmetry relative to the normal population birth distribution. There was no between-group difference in the seasonal distribution of birth when comparing the right-handed to the non-right-handed groups.ConclusionThe present study failed to provide support for a season of birth effect on atypical lateralisation of handedness in humans.

Asymmetry of the Brain: Development and Implications

“…Although not confirmed by other studies (85,114,159), independent reports in humans found significantly more LHs among the males born in winter (152,160). One hypothesis is that GE49CH26-Roussigne ARI 27 September 2015 14:54 seasonal variation in the mother's hormones, such as high levels of androgens during spring, could influence fetal development and contribute, together with genetic factors, to induce a left shift.…”

Social aspects of left-handedness

“…Upr kos svim ovim raz li ka ma, do mi na ci ja de sno ru ko sti u svim kul tu ra ma i ge o graf skim pod ruč ji ma uka zu je na to da ova oso bi na ni je re zul tat na u če nog. Do da nas ni je pro na đe no ni jed no dru štvo u ko jem se po ka zu je do mi na ci ja le vo ru ko sti [3,11,12].…”