Sex in our species: “Vive la différence!”

Primates are one of the animal orders with a higher degree of sexual dimorphism, in what has been considered a clear example of sexual selection. Within this order, however, there are obvious differences among species. Sexual dimorphism in the human species is very low, though we can observe several differences. In addition to primary sexual traits, secondary sexual differences are observable in both morphological and physiological features such as skull structure, the olfactory system and fat accumulation. Lastly, we can also observe behavioural differences that have strong cultural and social determinants behind them but also have an important biological base that can be narrowed down to differences in brain structure.