Sexual roles in deep prehistory are among the most intriguing puzzles still to solve. Here the author shows how men and women can be distinguished by scientific measurement in the prints and stencils of the human hand that occur widely in Upper Palaeolithic art. Six hand stencils from four French caves are attributed to four adult females, an adult male, and a sub-adult male. Here we take a step closer to showing that both sexes are engaged in cave art and whatever dreams and rituals it implies.