Absence of Cradling Bias In Autism Spectrum Disorders

Background: Autism spectrum disorder (ASD) is a known disorder of emotional relatedness – one in which ineffective social skills and deficits in empathy are considered defining features. With regards to ASD, researchers have generally focused on deficits in higher-order aspects of empathy such as Theory of Mind, but have relatively neglected more basic difficulties with social reciprocity exhibited by these individuals. More attention should be directed at deficits in the basic innate capacity for one human being to relate to another. A well-established social phenomenon, namely cradling bias (i.e., the preference to cradle an infant to the left of the body midline) is argued to be facilitated by a capacity for empathy.  Previous studies provide reason to suspect that this phenomenon taps into innate, basic empathic processes of relating to and bonding with another human being. 

Objectives: Direct systematic observation was employed to compare the occurrence of cradling bias in children diagnosed with autism spectrum disorders (ASDs), typically developing (TD) children, and mentally handicapped (MH) children. Standardized tests were employed to determine the influence of higher-order cognitive processes on cradling bias.

Methods: This study was a cross-sectional comparison of three groups: an ASD, a MH, and a TD group. Twenty ASD and 20 TD children, aged 5-15, and 16 MH children, aged 7-13, were asked to cradle a doll as if it was an infant he/she wanted to soothe or put to sleep. This was done on three separate occasions. Cradling bias was determined by the side preferred. All three groups were matched on gender (3:1 male to female ratio) and age (i.e., similar age ranges). A standardized test measuring intellectual functioning was administered. 

Results:  As hypothesized, cradling bias was found to be absent in the ASD children, compared to the leftward bias present in the TD and MH children. A chi-squared test of contingency revealed a significant result (χ²(2) = 7.98, p = 0.019), indicating that cradling side was contingent on group membership. Further analysis by partitioning indicated a significant  difference between the ASD and TD groups (χ²(1) = 7.62, p = 0.007, R = 9.00), but no difference between the TD and MH groups (χ²(1) = 1.45, p = 0.230, R = 0.33).

Conclusions: Findings support the argument that this phenomenon taps into innate, basic empathic processes, as this bias is present in both neurotypical and mentally handicapped children, but not in the ASD children. This is the first human population found not to have the leftward cradling bias, echoing Kanner’s (1943) original description of ASD individuals as “having come into the world with an innate inability to form the usually biologically provided affective contact with other people” (p. 250). Focused investigation of particular aspects of empathy may allow for a more nuanced understanding of the nature of the empathy deficits by which this disorder is characterised, which has implications for the management and treatment of affected individuals.