Having a sibling may help autistic people navigate their daily lives better, according to a new unpublished study.
Researchers presented the findings virtually at the 2021 International Society for Autism Research annual meeting this week. (Links to abstracts may work only for registered conference attendees.)
Many autistic people struggle with adaptive functioning, or the ability to communicate, socialize and perform daily tasks at an age-appropriate level. But regular social engagement with peers can help improve these skills, studies show.
For autistic people, regular social interactions can also come by way of siblings, said Nicole Rosen, a graduate student in Catherine Lord’s lab at the University of California, Los Angeles, at a press conference at the meeting.
“We know that the sibling relationship is considered one of the most transformative and meaningful relationships that an individual may have,” particularly because it can last a lifetime, she said.
Siblings are thought to have a positive influence on autistic people’s theory-of-mind abilities and social skills. The new work shows that they have a similarly positive effect on adaptive functioning.
“Siblings may represent a key medium” through which autistic people can improve these skills, Rosen says.
Lord, Rosen and their colleagues administered the Vineland Adaptive Behavior Scales, a caregiver questionnaire that measures daily-living skills and age-appropriate communication and socialization, to 208 people with autism or another developmental condition six times from age 9 to 26 years.
Participants with siblings improved their scores more than their only-child peers did over time. Those who were closest in age to a non-autistic brother improved at a faster rate than those closest in age to a non-autistic sister, the team found. And participants who were closest in age to a sibling of their same gender improved faster than those closest in age to a sibling of the opposite gender.
Birth order and number of siblings, on the other hand, did not affect the participants’ rate of improvement.
Autistic people of all racial backgrounds benefited from having a sibling, but the effect was strongest for Black participants, the researchers found. Differences among racial groups should be interpreted with caution, Rosen said, as this is the first study to look at the effect siblings have on adaptive functioning.
For now, the findings may be helpful for family-planning decisions, she says: Many parents are concerned about how a bigger family might affect an autistic child, but the results suggest that siblings are an important source of support.
If siblings can help shape an autistic person’s adaptive functioning, getting them involved in interventions may help to maximize the development of those skills, Rosen said.
Read more reports from the 2021 International Society for Autism Research annual meeting.