Essentialism stresses the biological roots of gender and sexuality, ignoring their historical and cultural variability: gender differences change over time, gender inequality varies across societies, mate selection criteria vary across societies. Indicators of gender inequality: ratio of males to females in primary, secondary and tertiary education. The higher the ratio, the higher the level of gender inequality: men as a percent of parliamentarians in the lower house (or the single house in unicameral political systems). The higher the ratio, the higher the level of gender inequality: participation rate of women in the paid labour force. The lower the rate, the higher the level of gender inequality: prevalence of female genital mutilation. The higher the prevalence the higher the level of gender inequality: the wealthier the country, the less gender inequality. People are transgendered when their gender identity does not exactly match the sex assigned to them at birth. They blur widely accepted gender roles by, for example, cross- dressing.