Greater male variability hypothesis

Greater Male variability hypothesis is a hypothesis that states that men exhibit a greater variability in their traits in contrast to women.

In terms of cognitive differences between sexes, men are more likely to score both very high and very low iq scores than the average as opposed to women who are more likely to score average results. Men also display greater variability in phenotype,leading scholars to believe that men are a heterogametic sex while female are a homogametic sex.

Examples

Males outperform females on most measures of quantitative and visuospatial abilities,which contribute to gender differences in standardized exams in mathematics and science.

According to a 2016 study," male variance is significantly greater than female variance in 238 (or 58 %) of the 410 cases. This proportion is larger than that observed for science (49 %) and for mathematics (42 %)." This study also states that men across all countries and studies display 14% higher variance than their female counterparts.

Fewer women pursue education in STEM(Science, Technology,Engineering, Mathematics) despite outperforming men in relevant subjects at school level. According to a 2018 study, which analysed gender differences in grades of 1.6 million students, found strong evidence for greater variance in grades recieved by males in contrast to females.

Causes

Selective pressure

A 2017 mathematical analysis by Theodore P. Hill and Sergei Tabachnikov posited evolutionary or selective pressure as cause for greater male variability.

if one sex is relatively selective, then more variable subpopulations of the opposite sex will tend to prevail over those with lesser variability; and conversely, if one sex is relatively non-selective, then less variable subpopulations of the opposite sex will tend to prevail over those with greater variability

The study further elaborated that if females were generally selective (pF < 0.5) while men were generally non selective (pM > 0.5) or both for most of their hunter gatherer history, it would have inevitably led to relatively greater male variability.

The selective pressure theory can be backed by recent genetic/genome analysis which uncovered the fact that only 1 male managed to reproduce/pass on his dna for every 17 females that did.