The term gender is essential in recent biological anthropology. After decades of critical discussion the differentiation into biological sex and social gender is accepted as especially useful. The distinction into sex and gender makes a more complex view at biological phenomenon such a sexual size dimorphism typical of Homo sapiens possible. Although sexual size dimorphism has a clear evolutionary basis and is caused by genetic and hormonal factors, socio-cultural factors such as gender role in society and gender typical workload influence the degree of sexual size dimorphism too.