The sensitivity of male children (5–15 years) with and without autism spectrum disorder (ASD) to the affective state of others was tested using an emotion recognition task. Only children without ASD could reliably differentiate between enjoyment and non-enjoyment smiles. Results are considered in terms of the social impairments of children with ASD.
Blampied, M., Johnston, L., Miles, L., & Liberty, K. (2010). Sensitivity to differences between enjoyment and non-enjoyment smiles in children with autism spectrum disorder. British Journal of Developmental Psychology, 28(2), 483-489. https://doi.org/10.1348/026151009X467621