Abstract The belief in the power of the imagination of parents, and especially of the mother, to influence the features of the foetus has been widespread since ancient times. The first reference is in Genesis 30:25–43. It tells the story of how Jacob showed his father-in-law’s ewes and goats coloured branches (stripped branches) during the mating season in order to produce spotted offspring. The theory refers not only to animals, but also to human beings, as various sources testify. The power of female imagination could extend from the moment of coitus through to the entire pregnancy, giving rise to congenital features in the foetus. Starting from the widespread idea of the female imagination as a disruptive factor in the entire process of the formation of the future individual, the aim of this article is to focus on one specific aspect of the question: namely, the origin and development of the belief that ‘bastard’ children resemble their putative fathers rather than their real fathers. To this end, the most significant medical and philosophical sources will be considered, from the origin of this belief, in the late Middle Ages through to the early modern period.
Alessandra Foscati (Sat,) studied this question.