Broadly based statistical studies into sexual behaviour are largely confined to the twentieth century. If we stretch the term sexological, however, we can find statistical studies as early as the sixteenth century.

François Rabelais (c. 1490-1553) checked the monthly distribution of christenings in his part of France and discovered a peak incidence in October and November - leading him to the conclusion that the first thaws of January and February resulted in increased sexual activity. A later French researcher, Villermé, had reported in 1831 on the basis of 17,000,000 births, that the maximum of French conceptions occur in April, May, and June.