Men

Men are adult human beings who are identified as male. Biologically, most men have XY chromosomes and produce androgens such as testosterone, which drive the development of male secondary sexual characteristics during puberty, including facial hair, a deeper voice, and increased muscle mass. The biology of sex and gender is variable: some people assigned male at birth may identify as transgender, and some individuals are intersex, with sex characteristics that do not fit typical definitions of male or female.

In reproduction, men typically contribute half of the genetic material in offspring through sperm. Sperm production begins at puberty and continues throughout many years, with fertility influenced by health and age. While biological factors are common, social and cultural identities of men vary widely across societies and historical periods.

Across cultures, expectations of what it means to be a man have included roles in family, work, leadership, and protection, but such norms differ widely and have evolved with social change. Contemporary discussions of gender emphasize voluntary and equal participation in civic life, family work, and decision-making, acknowledging that people of all genders may fill diverse roles.

Demographically, men currently comprise about half of many populations, though the sex ratio at birth slightly favors males in many populations. Life expectancy for men is generally shorter than for women in many regions, reflecting a combination of biological, behavioral, and social factors, with regional variations.