Early social communication in infants with fragile X syndrome and infant siblings of children with autism spectrum disorder.

The study did not follow infants over time, so it cannot show how social communication develops. The scoring captured the highest communication act during the play tasks, so it may miss the full pattern of everyday communication. The sample included few girls, so comparisons between boys and girls were not possible. The play tasks were designed to encourage social interaction, not to require requests, so communicative functions may not have been fully measured. Families may have enrolled because they were concerned about development, which could bias the sample. The measure used was later revised so that scanning between objects is no longer counted as communication. The siblings of children with autism looked similar to typically developing infants, so the design may have missed variability within that group.

Do not read the peek-a-boo finding as proof that social play improves communication in fragile X syndrome. The study observed communication during different play tasks and did not test an intervention.