A neonatal right-side preference makes a surprising romantic reappearance later in life. A preference in humans for turning the head to the right, rather than to the left, during the final weeks of gestation and for the first six months after birth1,2 constitutes one of the earliest examples of behavioural asymmetry and is thought to influence the subsequent development of perceptual and motor preferences by increasing visual orientation to the right side3,4. Here I show that twice as many adults turn their heads to the right as to the left when kissing, indicating that this head-motor bias persists into adulthood. My finding may be linked to other forms of sidedness (for example, favouring the right foot, ear or eye) that do not become established until long after the newborn head-turning preference has disappeared5,6.