Infants' knowledge of their own species

Abstract

Recognition of individuals at first sight is important for social species and can be achieved by attending to facial or body information. Previous research suggests that infants possess a perceptual template for evolutionarily relevant stimuli, which may include humans, dangerous animals (e.g. snakes), but not non-dangerous animals. To be effective, such a mechanism should result in a systematic preference for attending to humans over non-dangerous animals. Using a preferential looking paradigm, the present studies investigated the nature of infants' early representation of humans. We show that 3.5-and six-month-old infants attend more to human beings than nonhuman primates (a gorilla or monkey) which are examplars of non-dangerous animals. This occurred when infants were presented with head or body information in isolation, as well as when both are presented simultaneously. This early preference for humans by 3.5 months of age suggests that there is a basic representation for humans, which includes both head and/or body information. However, neonates demonstrated a preference only for human faces over nonhuman primate faces, not for humans over non-human primates when the stimuli were presented with both head and body simultaneously. The results show that although neonates display a preference for human faces over others, preference for the human body only develops later, in the first few months of life. This suggests that infants have acquired some knowledge about the human body at 3.5 months of age that may have developed from their privileged experience with other humans in the first few months of life, rather than an innate ability to detect humans in their entirety.

Preference for human eyes in human infants

“…Heron-Delaney, Wirth, and Pascalis (2011) found, however, a neonatal preference toward human faces compared to macaque faces using colored pictures, concluding that a few days of exposure to human faces was sufficient to allow them to differentiate human from non-human primate faces. Di Giorgio, Leo, Pascalis, and Simion (2012) using similar stimuli equated for low-level perceptual properties failed to replicate such a preference for human faces in newborns.…”

Listening to the calls of the wild: The role of experience in linking language and cognition in young infants

“…Caregivers played this soundtrack at home to their infants on a precise tapering schedule (Heron-Delaney, Wirth, & Pascalis, 2011; Pascalis et al, 2005; Scott & Monesson, 2009). Infants listened to the soundtrack everyday in Week 1, every other day in Week 2, and three times per week thereafter.…”

“…For example, providing 12-month-old infants with brief (less than one minute) exposure to monkey faces enabled them to reinstate their developmentally prior ability to discriminate among novel monkey faces, even months after their face perception had been tuned specifically to human (and no longer monkey) faces (Fair et al, 2012; for parallel work in music perception, see Hannon & Trehub, 2005; Trehub & Hannon, 2006). In addition, providing infants with persistent exposure—from 6 months (when infants still discriminate among monkey faces) until 9 months (when they would otherwise have tuned specifically to human faces)—enabled infants to maintain their perceptual discrimination of monkey faces (Pascalis et al, 2005; Scott & Monesson, 2009; for parallel work in other-race face perception, see Heron-Delaney, Wirth, & Pascalis, 2011). Combined, this evidence showcases infants’ perceptual plasticity and the powerful effects of exposure.…”

The many faces of research on face perception

“…In their paper on face processing in infants, HeronDelaney et al [14] emphasize the importance of being able to distinguish between members of your own and other species. First, they review previous research demonstrating that the ability to distinguish human from non-human faces emerges early in infancy.…”

“…Whereas Heron-Delaney et al [14] compare and contrast face-and body-processing abilities in individuals of different ages (e.g. neonates and older infants), Parr [15] compares face-processing abilities in different primate species, discussing research demonstrating that, like human infants, infant macaques and gibbons prefer to look at faces relative to non-face objects and that experience is important for discriminating between faces from different categories (e.g.…”