Expression of emotion by infants with and without disabilities
The aim of this research was to provide a detailed description of emotional expression in infants, with and without disabilities. 30 typically-developing infants (aged four to five-and-a-half months)were video-recorded in four situations: immunisation, oral polio vaccination, social play and response to a surprise toy. These were designed to elicit a range of emotional behaviours. 20 infants with congenital, developmental disabilities of varying aetiologies were matched on developmental age and filmed in the same situations. Facial expressions were coded using the Maximally Discriminative Facial Movement Coding System (Max) (Izard, 1983) and emotional behaviour during interaction with Monadic Phases (Tronick, Krafchuk, Ricks, Cohn & Winn, 1980). Infants with disabilities showed fewer expressions of pain involving the whole face, and more expressions resembling blends of pain with fear, than typically-developing infants. This was due to several of these infants drawing back the mouth into a horizontal-stretch, rather than opening it fully. There was no group difference in time to respond to needle penetration with a pain expression, although median response time was higher for infants with disabilities. Both groups of infants had negative correlations between reaction time to pain and intensity of pain expression and time to recovery, indicating that infant emotion systems are integrated and coordinated with other behavioural systems. Expressions of infants with disabilities were also more fleeting and they showed reduced muscle movement in the upper-face and unconventional movements in the mid-face. They also showed fewer joy and interest expressions using the whole face, and more uncodeable expressions. Carers and female students were shown pictures of the infants' facial expressions and asked to describe the emotions they showed. There was no difference between carers and students, in accuracy of discriminating expressions of typically-developing infants, supporting claims of innate recognition of facial expressions. Expressions of sadness, fear, joy and surprise of infants with disabilities were discriminated less accurately than those of typically-developing infants. All expressions of infants with disabilities were perceived as giving significantly less intense signals than those of typically-developing infants. There were some systematic errors in judgement, with anger and pain, fear and sadness and interest and surprise expressions being mistaken for each other. This was explained in terms of morphological similarities between these expressions. Carers of infants with disabilities were more accurate at judging their own infant, but otherwise no more accurate than other judges. Coding of interactive behaviour revealed that infants with disabilities showed significantly more social attend and avert, and less social play, object attend and object play, than typicallydeveloping infants. These differences were attributed to delayed changes in functional use of eye contact and greater need to use aversion as a mechanism for regulating arousal in infants with disabilities. Carers of infants with disabilities showed less social play than those of typicallydeveloping infants. In these dyads, there was some evidence of lower frequency of agreement between infant and carer behaviours. This study provides a more comprehensive description of emotional behaviour, and involves a smaller range of developmental ages and a wider range of emotion-eliciting situations, than previous studies. The findings are useful for informing interventions for infants with disabilities and their carers.