A recent mixed-methods study revealed both similarities and differences in sibling relationships between families with and without a child with autism.

In the study, published in the Journal of Autism and Developmental Disorders, researchers provided insights into the perspectives of typical siblings and mothers regarding these relationships. They recruited 75 Israeli Hebrew-speaking families: 29 families with a child with autism and 46 families with only typical children. Participants were older typical siblings (mean [SD] age = 8.78 [2.05] years in the autism group, 9.12 [2.06] years in the typical group) and their mothers (mean [SD] age = 39.1 [5.32] years in the autism group, 37.33 [3.83] years in the typical group).

Inclusion criteria for the autism group were families in which a younger sibling had a diagnosis of autism and the older sibling was typically developing. All children with autism had diagnoses from authorized medical/health care centers using the Autism Diagnostic Observation Scales (ADOS) as part of the diagnostic battery.

Data collection involved:

• Sibling Relationship Questionnaire (SRQ) completed by siblings and mothers
• Open-ended interviews with 84% of participants
• Vineland Adaptive Behavior Scales (VABS) for children with autism

Quantitative analysis included multivariate analyses of variance (MANOVA), t tests, and Pearson correlation tests. Qualitative analysis employed inductive, data-driven coding of interview transcripts.

Among the key findings were:

• Siblings of children with autism reported similar levels of overall warmth, conflict, rivalry, and power in their relationships compared with siblings in typical families.
• Mothers of children with autism reported less warmth and closeness as well as less conflict between their children compared with mothers of only typical children.
• Both mothers and siblings in families with a child with autism reported less intimacy and less quarreling in the sibling relationship.
• Qualitative analysis revealed that siblings focused on present experiences, whereas mothers also considered long-term processes in the relationships.

Quantitative findings included:

• No statistically significant between-group differences were found in siblings' reports of SRQ factors: warmth/closeness (F1,72 = 1.403; P = .24; η2 = .019), conflict (F1,72 = 2.87; P = .095; η2 = .038), rivalry (F1,72 = 2.133; P = .149; η2 = 0.029), and relative status power (F1,72 = 0.22; P = .642; η2 = 0.003).
• Siblings of children with autism reported less intimacy (F1,72 = 6.08; P = .016; η2 = .078) and quarreling (F1,72 = 4.27; P = .042; η2 = .056) compared with siblings in typical families.
• Mothers of children with autism reported less warmth/closeness (F1,72 = 5.63; P = .02; η2 = .073) and less conflict (F1,72 = 6.66; P = .012; η2 = .085) compared with mothers in typical families.
• Mothers in the autism group reported lower levels of intimacy (F1,72 = 20.23; P = .00; η2 = .219), quarreling (F1,72 = 4.94; P = .029; η2 = .064), prosociality (F1,72 = 4.57; P = .036; η2 = .06), sibling nurturance (F1,72 = 8.29; P = .005; η2 = .103), similarity between siblings (F1,72 = 14.2; P = .00; η2 = .165), and competition (F1,72 = 7.42; P = .008; η2 = .093).
• Maternal partiality showed a preference for the younger sibling in both groups (autism group: t27 = –3.17; P = .004; typical group: t45 = –3.59; P = .001).
• In the autism group, children's and mothers' reports correlated only in the conflict factor (r29 = .454; P = .0103). In the typical group, correlations were found for conflict (r46 = .410; P = .004) and warmth/closeness (r46 = .472; P = .001).
• Vineland Adaptive Behavior Scales scores for children with autism varied, with a mean (SD) score of 81.07 (15.547); range, 56–127.

Four main themes emerged from the interview analysis:

• Inseparable: common to both groups and informants, describing positive and negative aspects of sibling relationships
• The younger vs older: highlighting roles, disparities, and asymmetry in relationships
• The bigger picture: unique to mothers, focusing on changes and processes in relationships.
• The unsaid word: specific to the autism group, referring to the younger sibling's condition without explicitly using autism terminology.

The study revealed less agreement between mothers' and children's perspectives in the autism group compared with the typical group. Notably, only one child and one mother in the autism group explicitly used the terms 'autism' or 'spectrum' during interviews.

Additional findings revealed:

• No statistically significant correlations were found between siblings' age and SRQ measures, except for a moderate negative correlation (r44 = –.31, P = .037) between older typical siblings' age and rivalry score in the typical group.
• The male:female ratio among siblings with autism (86.2% male) was similar to the ratio reported in Israel.
• Family income levels and maternal education were similar between groups, with no significant differences (income: F1,69 = 3.09; P = .08; maternal education: F1,73 = 2.78; P = .10).
• The siblings' age gap was not significantly different between groups (F1,73 = 0.98; P = .33), with a mean (SD) of 2.72 (1.36) years in the autism group and 2.46 (0.92) years in the typical group.

Limitations of the study included a focus on sibling pairs with younger siblings with autism only; a small sample size, particularly for female siblings with autism; a volunteer sample potentially skewed towards research-positive families; the cross-sectional design limiting developmental insights; and a lack of direct assessment of typical siblings for cognitive and social measures, including broader autism phenotype.

The researchers emphasized the importance of considering both sibling and maternal perspectives in future research and clinical work with families of children with autism. They suggested further investigation into intimacy in sibling relationships, the nature of sibling conflicts, and longitudinal studies to examine changes in relationships and perspectives over time. Additionally, the study highlighted the need for research on sibling relationships in multiplex families with more than one child with autism and in families where the older sibling has been diagnosed with autism.

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.