Individuals with Autism Exhibit Reduced Sensitivity to Infant Cuteness

Background: Konrad Lorenz theorized that the neotenous physical features of the baby schema (e.g., round face and large eyes) confer an adaptive advantage by motivating caretaking behavior that increases the likelihood of offspring survival (Lorenz, 1943). Indeed, recent empirical evidence indicates that infant photographs manipulated to be more neotenous not only elicit higher ratings of cuteness and feelings of caretaking in typically developing (TD) adults, but also generate greater activation in the nucleus accumbens, a neural structure mediating the processing of reward value (Glocker et al, 2009a,b). For individuals with autism spectrum disorders (ASD), impairments in social interaction may in part result from reduced reward value assigned to social stimuli (Mundy and Neal, 2001; Dawson et al, 2004; 2005). The current study examined whether adults with ASD are less responsive to infant cuteness, a salient social reward for TD individuals.

Objectives:   To determine whether adults with ASD differ from TD adults in their perceived cuteness of systematically manipulated baby schema.

Methods: As detailed in Glocker et al 2009, photographs of 17 infants were anthropometrically altered to produce three naturalistic portraits that displayed either high (round face, high forehead, big eyes, small nose and mouth), low (narrow face, low forehead, small eyes, big nose and mouth) or unmanipulated baby schemas. These 51 images were rated on perceived cuteness on a 5 point Likert scale by 9 adults with ADOS-confirmed diagnoses of ASD and 14 TD comparison participants. The groups did not differ in age or estimated IQ. In a second control condition, participants rated the same images on the size of the infant’s eyes.

Results:  A mixed model ANOVA, co-varying gender, with group (TD vs ASD) as the between group factor and condition (cuteness vs eye size) and baby schema (low, medium and high) as the within group factors produced a significant three way interaction between group, condition and baby schema (F (2, 20) = 3.85, p = .039, h_p²=.278). Follow-up tests revealed that this interaction was driven by the groups differing across the three baby schema types for cuteness ratings, yet performing similarly across the three baby schema types for eye size ratings. Both the TD and ASD groups therefore increased their eye size ratings to increasingly neotenous baby images, but this manipulation only elicited an increase in cuteness ratings for the TD group.

Conclusions: The present study reports reduced sensitivity in ASD to infant cuteness. Although the ASD group was comparable to the TD group in detecting the physical changes associated with increasing neoteny in infant faces, they were alone in failing to modulate their cuteness ratings in accordance with these changes. These findings suggest that individuals with ASD may be less affected by characteristics of infant cuteness, and provide additional evidence for abnormal reward processing of social stimuli in ASD. We anticipate that these results will persist within the much larger sample that will be obtained by the start of the conference.