Gender inequality is the social phenomenon in which people are not treated equally on the basis of gender. The treatment may arise from distinctions regarding biology, psychology, or cultural norms prevalent in the society. Some of these distinctions are empirically grounded, while others appear to be social constructs. While current policies around the world cause inequality among individuals, it is women who are most affected. Gender inequality weakens women in many areas such as health, education, and business life. Studies show the different experiences of genders across many domains including education, life expectancy, personality, interests, family life, careers, and political affiliation. Gender inequality is experienced differently across different cultures and also affects non-binary people. Sex differences Biology Natural differences exist between the sexes based on biological and anatomic factors, mostly differing reproductive roles. Biological differences include chromosomes and hormonal differences. There is a natural difference also in the relative physical strengths (on average) of the sexes, both in the lower body and more pronouncedly in the upper-body, though this does not mean that any given man is stronger than any given woman. Men, on average, are taller, which provides both advantages and disadvantages. Women, on average, live significantly longer than men, though it is not clear to what extent this is a biological difference - see Life expectancy. Men have larger lung volumes and more circulating blood cells and clotting factors, while women have more circulating white blood cells and produce antibodies faster. Differences such as these are hypothesized to be an adaptation allowing for sexual specialization. Psychology Prenatal hormone exposure influences the extent to which a person exhibits typical masculine or feminine traits. Negligible differences between males and females exist in general intelligence. Women are significantly less likely to take risks than men. Men are also more likely than women to be aggressive, a trait influenced by prenatal and possibly current androgen exposure. It has been theorized that these differences combined with physical differences are an adaptation representing sexual division of labour. A second theory proposes sex differences in intergroup aggression represent adaptations in male aggression to allow for territory, resource and mate acquisition. Females are (on average) more empathetic than males, though this does not mean that any given woman is more empathetic than any given man. Men and women have better visuospatial and verbal memory, respectively. These changes are influenced by the male sex hormone testosterone, which