Body odours as putative chemosignals in the father-child relationship: New insights on paternal olfactory kin recognition and preference from infancy to adolescence.

Children's body odours are effective chemical cues in the parent-child relationship. Mothers can recognize the odour of their child and prefer this odour over that of unfamiliar children. This effect is mediated by genetic similarity and developmental stage and is therefore suited to promote parental care at pre-pubertal stage, while facilitating incest avoidance at (post-)pubertal stage. The present study tested whether similar mechanisms apply to fathers. Therefore n = 56 fathers evaluated body odour samples of their own and of unfamiliar children in varying genetic and developmental stages. Genetic status was determined by human leucocyte antigen (HLA) profiling, developmental status by standardized assessment of pubertal status and steroid hormone concentration (estradiol, testosterone). Similar to mothers, fathers identified their own child's body odour above chance and preferred that odour. The paternal preference did not relate to HLA similarity but decreased with increasing age of the child. The decline was associated with higher pubertal stages in daughters only, which supports the hypothesis of odour-mediated incest prevention in opposite-sex parent-child dyads.