A predisposition for biological motion in the newborn baby

TLDR

An inborn predisposition to attend to biological motion has been theorized but only demonstrated in domestic chickens, with no preference reported in human infants under three months. The study examined 2‑day‑old infants by familiarizing them with point‑light animations and measuring their discrimination and spontaneous preference for biological versus nonbiological motion. Newborns discriminated between two motion patterns and preferentially looked longer at biological motion, especially upright displays, supporting the view that biological‑motion detection is an intrinsic, evolutionarily ancient visual capacity.

Abstract

An inborn predisposition to attend to biological motion has long been theorized, but had so far been demonstrated only in one animal species (the domestic chicken). In particular, no preference for biological motion was reported for human infants of <3 months of age. We tested 2-day-old babies' discrimination after familiarization and their spontaneous preferences for biological vs. nonbiological point-light animations. Newborns were shown to be able to discriminate between two different patterns of motion (Exp. 1) and, when first exposed to them, selectively preferred to look at the biological motion display (Exp. 2). This preference was also orientation-dependent: newborns looked longer at upright displays than upside-down displays (Exp. 3). These data support the hypothesis that detection of biological motion is an intrinsic capacity of the visual system, which is presumably part of an evolutionarily ancient and nonspecies-specific system predisposing animals to preferentially attend to other animals.