Study Looks at Autism Risk in Infants

Vulnerabilities that increase risk in sibilings of autistic children

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A recent study conducted by the Kennedy Krieger Institute in collaboration with the University of Delaware suggests that infants at risk for developing autism who infrequently gaze at other people when not prompted may be at an even higher risk of developing the disorder. The same study also found that high-risk infants display the same cause-and-effect learning skills demonstrated by low-risk infants of the same age group.


In all 25 infant siblings of children with autism (high-risk group) were studied in addition to 25 infants with no family history of the disorder (low-risk group). All infants were six months of age. Those identified as high-risk are 25 times more likely to develop autism than those who are low-risk. It is projected that about 20 percent of the high-risk infants in this study will receive a diagnosis of autism by their third birthday.

Dr. Rebecca Landa, corresponding study author and director of Kennedy Krieger's Center for Autism and Related Disorders, said the study demonstrated “a particular vulnerability in high-risk siblings at six months of age.”

Landa said a subtle indicator for possibly developing the disorder included a lack of social interaction and self-engagement in high-risk infants when compared to peers. These infants still respond typically to caregivers, however, “making for a subtle difference that could be easily overlooked by both parents and some professionals,” Landa said.

The study also yielded a lack of evidence supporting impaired associative learning in high-risk infants as both groups exhibited cause-and-effect learning abilities. Once the infants learned that pulling a joystick resulted in music, they increased how often they activated the toy’s music. Such evidence points to a relative strength in older children afflicted with the disorder, which may explain why autistic children respond favorably to teaching techniques with predictable reward systems. 

High-risk infants “still have the capacity to learn cause-and-effect as well as their low-risk peers at this young age,” Landa said. 

Infants in the high-risk category also tended to want access to the musical toy as opposed to social interaction with a caregiver when the caregiver was not actively engaged with the infant. 

Results of the study, funded by grants from the National Institutes of Mental Health, will be published in the September issue of the Journal of Child Psychology and Psychiatry.

Reviewed by: 
Review Date: 
September 15, 2010
Last Updated:
February 16, 2011