Sex Ratio

Sex ratio is the ratio of males to females in a population. The primary sex ratio is the ratio at the time of conception, secondary sex ratio is the ratio at time of birth, and tertiary sex ratio is the ratio of mature organisms. Typically, as the population increases today the ratio from men to women is uneven; for every 96 men there are 100 women due to the high death rate in males.

The human sex ratio is of particular interest to anthropologists and demographers. In human societies, however, sex ratios at birth may be considerably skewed by factors such as the age of mother at birth, and by sex-selective abortion and infanticide. The CIA estimates that the current world wide sex ratio at birth is 107 boys to 100 girls. In 2010, the global sex ratio was 986 females per 1,000 males and trended to reduce to 984 in 2011.