The Sibling Bond May Decide Who Cares for Autistic Adults Tomorrow

When parents of autistic children grow old, someone must take over their care. In many families, that responsibility falls quietly on the shoulders of the neurotypical sibling. A new study published in Frontiers in Developmental Psychology suggests that whether teenagers actually intend to assume that role decades from now depends far less on parental pressure than researchers expected, and far more on something deceptively simple: how much they enjoy spending time with their autistic brother or sister today.

The research, conducted by Jenna H. Beffel Tolman of Hope College and Amy K. Nuttall of Michigan State University, examined 48 adolescent neurotypical siblings and their mothers. The teenagers, aged between 13 and 17.8 years, each had an autistic sibling living at home. The autistic siblings themselves ranged from 4.7 to 20.9 years old, and nearly 80 percent were male. Rather than relying solely on questionnaires, the team combined self-report measures with direct observation of mother-teen interactions, a methodological choice that allowed them to capture helping behavior as it actually unfolded rather than as families remembered it.

The observational component centered on a 15-minute conflict discussion adapted from the Parent-Child Disclosure Task, a standardized procedure in which mothers and teenagers talk through a real disagreement in their relationship. Trained coders then applied the Iowa Family Interactions Rating Scales, a well-validated coding system that quantifies behavioral exchanges between family members. The researchers focused on one specific code: prosocial behavior directed toward the mother, rated on a 9-point scale capturing cooperation, sensitivity, and helpfulness. Before any data were coded, the primary investigator completed a 6-week online training program and achieved excellent reliability with master coders, with an intraclass correlation of 0.97 for the prosocial behavior code.

Sibling relationship quality was measured with the Network of Relationships Inventory-Social Provisions Version, a 30-item questionnaire assessing six dimensions of the bond: reassurance of worth, affection, companionship, instrumental aid, reliable alliance, and intimate disclosure. The nurturance subscale was deliberately excluded because it conceptually overlapped with caregiving itself, the outcome being predicted. Caregiving intentions were captured with a single 7-point item asking teenagers how much they agreed with the statement that they planned to be involved with their autistic sibling when they were adults. Mothers answered a parallel item about their own expectations for their teen’s future involvement.

The statistical results were striking in their asymmetry. In the first regression model, sibling relationship quality emerged as a powerful predictor of caregiving intentions, with a standardized coefficient of 0.77 and a p-value below 0.001. The correlation between the two variables was 0.76, among the strongest associations one could hope to find in family research with a sample this size. The full model explained 59 percent of the variance in teenagers’ stated intentions. Mothers’ caregiving expectations, by contrast, showed no significant association with their teenagers’ plans, and the hypothesized interaction between relationship quality and maternal expectations failed to materialize.

The second model told a similar story about prosocial behavior. Although teenagers who displayed more helping behavior toward their mothers during the observed conflict discussion did show a modest positive trend toward higher caregiving intentions, the association fell just short of statistical significance at p = 0.059. The full model explained only 12 percent of the variance, and the hypothesized moderating effect of maternal expectations was absent here as well. The authors suggest that this null finding may reflect a conceptual distinction between low-cost prosocial behavior, such as everyday helpfulness toward a parent, and high-cost prosocial behavior, such as the sustained time and energy that caring for an autistic sibling would demand. Prior evidence indicates these two categories of helping are not strongly related to one another.

Why did mothers’ expectations carry so little weight? The researchers point to prior work showing that among families of individuals with learning disabilities, siblings’ and parents’ expectations for future caregiving roles match only about half the time. More recent research among siblings of individuals with intellectual and developmental disabilities suggests that parent characteristics are less closely tied to siblings’ future planning than sibling characteristics are. In other words, the sibling relationship itself may be the salient psychological anchor, while parental hopes operate in a different motivational domain that teenagers simply do not integrate into their own decision-making at this developmental stage.

The findings arrive at a moment when the question of adult autism care has been described as a crisis on the horizon. Aging parents may need assistance caring for their autistic children, and an absence of appropriate care can have long-term consequences for the autistic individual’s wellbeing. The majority of adolescent neurotypical siblings report intending to be involved in caring for their autistic sibling in the future, and when siblings do provide care, it represents an important source of support for families. Yet the authors are careful to emphasize that not every sibling will feel able or comfortable assuming a caregiving role, and that respecting this diversity of willingness is essential.

The study has limitations that temper interpretation. The sample was relatively homogeneous, with 90 percent of the neurotypical siblings identifying as White/Caucasian, and the researchers were unable to verify autism spectrum disorder diagnoses independently. The single-item measure of caregiving intentions asks about future involvement broadly, a term that could encompass anything from minimal support activities to taking on a full-time caregiver role. Because the outcome variable was positively skewed, the team tested logarithmic and inverse transformations, then applied a Yeo-Johnson power transformation in R, finding that the transformed results did not differ from the untransformed ones. Post-hoc power analyses confirmed that all models were powered above 0.80 despite the modest sample size.

For families and clinicians, the practical implication is clear: if the goal is to support neurotypical siblings in feeling able and comfortable with future involvement, attention may be better directed toward strengthening the sibling bond itself rather than toward explicit parental expectations. Future research, the authors note, should include more diverse samples, narrower definitions of caregiving, and longitudinal data to determine whether adolescent intentions actually translate into adult caregiving behavior. What the present study establishes is that the relationship teenagers build with their autistic siblings today, measured in fun time, affection, and intimate disclosure, may be the strongest psychological foundation for the care families will rely on tomorrow.

Subject of Research: The influences of prosocial behavior and family factors on future caregiving intentions among adolescent neurotypical siblings' of autistic individuals

Article Title: The influences of prosocial behavior and family factors on future caregiving intentions among adolescent neurotypical siblings' of autistic individuals

Article References: Beffel Tolman, J. H., & Nuttall, A. K. (2026). The influences of prosocial behavior and family factors on future caregiving intentions among adolescent neurotypical siblings' of autistic individuals. Frontiers in Developmental Psychology, 4, Article 1958446. https://doi.org/10.3389/fdpys.2026.1958446

Image Credits: AI Generated

DOI: 10.3389/fdpys.2026.1958446

Keywords: influences, prosocial, behavior, family, factors, future, caregiving, intentions, adolescent, neurotypical, siblings', autistic