Descriptive Analysis of Social Interaction and Communication Skills of Autistic Children According to Sibling Status and Characteristics

Article information

Psychiatry Investig. 2024;21(1):44-51
Publication date (electronic) : 2024 January 22
doi :
1Department of Psychiatry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
2Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea
Correspondence: Hee Jeong Yoo, MD, PhD Department of Psychiatry, Seoul National University Bundang Hospital, 82 Gumi-ro 173beon-gil, Bundang-gu, Seongnam 13620, Republic of Korea Tel: +82-31-787-7436, Fax: +82-31-787-4058, E-mail:
Received 2023 June 21; Revised 2023 August 22; Accepted 2023 September 21.



Sibling relationships in early childhood can have a positive impact on children’s social interaction and communication skills. Similarly, autistic children can benefit from interactions with their siblings, who can serve as readily available partners for social interaction. However, there is a lack of research on the effects of siblings based on specific characteristics of the sibling. Therefore, the aim of this study is to compare social interactions and communication skills of autistic children based on sibling status and characteristics.


We conducted a retrospective data review involving 895 autistic children and their siblings at Seoul National University Bundang Hospital. Variety of diagnostic assessments or questionnaires were administered. Based on the characteristics of the data, Quade’s test for nonparametric analysis of covariance was used to compare autism-related symptoms and levels of functioning of the autistic child according to 1) sibling status, 2) birth order, 3) sex, and 4) diagnosis of the sibling. Pearson correlation was used to explore associations between the sibling age gap and different clinical scores.


Having siblings was associated with fewer difficulties in restricted and repetitive behaviors. Based on the comparison of the Autism Diagnostic Interview-Revised scores, autistic children with multiple siblings demonstrated better nonverbal behaviors. Autistic children with autistic siblings experienced greater difficulties in social interactions and communications, such as peer relationships, sharing enjoyment, and engaging in social imitative play.


The study revealed differences in social interactions and communication skills of autistic children based on sibling status, birth order, affected sibling, age gap, and sex.


Sibling interaction is one of the first and longest-lasting relationships an individual experience. Sibling interactions provide children with opportunities to share experiences and emotions, as well as to practice various communication skills. Through these interactions, children often acquire a wide range of social skills that are crucial for their development. In fact, children are more likely to engage with their siblings than with their parents in certain types of interactions, such as nonverbal communication [1]. Studies have shown that children with siblings have higher social competence compared to those without siblings [2]. Moreover, it has been observed that children with siblings have a better understanding of others and tend to learn social skills by imitating their siblings [3,4]. These sibling interactions during early childhood have a lasting impact on social skill development, extending into early adolescence, making siblings an important source of social skill development [5]. Autism is characterized by difficulties in social communication and interaction, along with the presence of restricted or repetitive behaviors and interests (RRBs). These difficulties can hinder the autistic child’s ability to interact with peers, which is an important factor in maximizing their potential to adjust to their surrounding environment. Similar to typically developing children, siblings can provide opportunities for autistic children to interact with individuals of similar age and developmental stage at home, allowing them to practice and apply the skills they have learned in a comfortable setting. Studies have demonstrated that older siblings can positively influence the cognitive, academic, and communication skills of autistic children [6], as well as their social playing skills [7-9]. Additionally, autistic children have shown more initiation responses from their siblings compared to their parents [10], indicating that siblings can serve as a promising source of social interaction improvement. Moreover, specific characteristics of siblings have been linked to distinct social skill development in autistic children and other psychiatric disorders. According to Ben-Itzchak et al. [10], individuals with older siblings exhibited better social communication skills and adaptive behaviors compared to those without siblings. Similarly, a study done by Montes [11] demonstrated that those with older siblings were less likely to experience mental health or behavioral problems. Having multiple siblings was associated with better social skills due to the increased opportunities for imitation and social interaction, yet the sex of the sibling appeared to have no significant impact on the social functioning of the autistic child [12]. Furthermore, a meta-analysis by Cuskelly et al. [13] delved into the influence of siblings on autistic children. Interestingly, while some studies, like Matthews et al. [14], revealed the benefits of having an older sibling in terms of tasks involving false beliefs or nonverbal tasks, others, such as one by Brewton et al. [15] demonstrated that the adaptive skills were associated with the social skills of the autistic child. In summary, existing research has explored how siblings affect social skills in autistic children, although it has been somewhat limited in the range of variables examined. More notably, inconsistencies in the results have emerged. Some potential explanations for these discrepancies include, include the utilization of different outcome measures evaluated by different diagnostic tools, uncertainties surrounding the diagnosis of certain participants, and the relatively small size of study population [13]. To address these limitations, we designed this study as a single-center investigation involving over 400 participants who were assessed using consistent diagnostic criteria. Our aim was to explore various sibling variables and their effects on the social functioning of autistic children.

This current study aims to examine the manifestation of symptoms in autistic children based on sibling status, birth order, sex, sibling’s diagnosis of autism, and age gap. The study hypothesized that autism-related symptoms, measured by various clinical assessment tools, will differ according to these sibling characteristics. First, given that sibling interaction provides opportunities for social imitation and the practice of play skills [7], we anticipate that the group with siblings will show less difficulties in social skills compared to autistic children without siblings. Second, children with older siblings, who are expected to show proactive behavior to younger siblings, are likely to present better social communication and interaction skills [16]. Third, similar to previous studies [11], the sex of the siblings will not significantly affect the social skill development of the autistic child. Fourth, being a “concordant pair,” the case in which the sibling is also diagnosed with autism, may limit active sibling interactions involving identifying social cues, responses, imitation, and/or joint attention. Lastly, sibling pairs with smaller age gaps will be associated with better social interaction skills, as closer age proximity would mean that the sibling may share similar levels of maturity with common interests or day-to-day activities.



This was a retrospective study that included 895 autistic children and their siblings, aged between 2 and 13 years, who were part of a larger genetic study conducted at Seoul National University Bundang Hospital. Various questionnaires were sent via post prior to the appointment and collected during the families’ visit to the clinic, where diagnostic and various examinations to measure the level of functioning (i.e., intelligence) were administered. The same evaluation process was conducted for both the autistic child and their sibling. The diagnostic assessments, including the Autism Diagnostic Observation Schedule (ADOS or ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R), were administered by trained researchers. All the evaluations were video-recorded and reviewed for reliability and supervision. Based on all the acquired information, child and adolescent psychiatrists confirmed the diagnosis using the best clinical estimate diagnosis. The use of fully anonymous data for this study was approved by the Institutional Review Board at Seoul National University Bundang Hospital (IRB no.: B-2301-807-102).



The ADI-R [17] is a structured caregiver interview used to diagnose autism. The interview consists of four large domains and subdomains: reciprocal social interaction (use of nonverbal behaviors, peer relationships, shared enjoyment, socioemotional reciprocity), communication (nonverbal: use of gestures, play skills; verbal: conversational interchange, stereotypes or idiosyncratic speech), RRBs (circumscribed pattern of interest, routines or rituals, stereotyped or repetitive motor movements, preoccupations with part of objects), and the presence of abnormal behavior before 36 months. The verbal and nonverbal domains are evaluated separately, based on the expressive language skills of the child. Higher scores on the ADI-R indicate greater severity of autism.


ADOS-2 [18] is a standardized observational assessment used to evaluate social interaction and communicative skills of a child. Trained administrators interact with the child, and there are five different modules based on age and expressive language ability. Each module has its own diagnostic algorithm, and the calibrated severity scales (CSS) are used for comparison between different modules, ranging from 1 to 10. The summation of the two domains, social affect (SA) and RRB, results in a total score. Higher ADOS-2 SA, RRB, and total CSS scores indicate greater symptom severity.

Vineland Adaptive Behavior Scale, Second Edition

The Vineland Adaptive Behavior Scale, Second Edition (VABS-II) [19] is a parent-rating questionnaire that measures adaptive functioning. It includes four domains: communication, daily living skills, socialization, and motor skills. A total composite score is calculated based on these domains. Higher scores on the VABS-II indicate better adaptive behavior, while lower scores may suggest developmental delay.

Social Communication Questionnaire

The Social Communication Questionnaire (SCQ) [20] is a caregiver-completed questionnaire with 40 questions. Higher scores on the SCQ indicate greater symptom severity. While there are two versions of the questionnaire, the current version, which asks caregivers to base the ratings on the past three months, was utilized. In this study, the Korean translated and validated version of the SCQ was used [20].

Child development questionnaire

To obtain information on the child’s developmental history, the research team created a questionnaire to gather information about perinatal and prenatal factors. This questionnaire, completed by parents, asked about events during pregnancy (e.g., age of parents, complications, illnesses, and medication use) and after birth (e.g., newborn conditions, post-birth treatments, history of education and interventions). For this study, only the question items regarding the child’s sibling status and birth order were used.

Data analysis

Based on the child development questionnaire, autistic children were grouped according to sibling status (i.e., no sibling, sibling) and birth order (i.e., older sibling, younger sibling, twin, or having multiple siblings). Basic demographics of autistic children based on sibling groupings were compared using independent t-tests or univariate analysis of covariance for continuous variables (i.e., age) and chi-square for categorical variables (i.e., sex). Clinical characteristics represented by the autistic child’s total or domain scores of the ADI-R, ADOS-2, VABS-II, and SCQ were compared according to sibling status and birth order. Given the non-normal distribution of dependent variables based on Shapiro–Wilk and the violations of homogeneity of variances or homogeneity of regression slopes, nonparametric tests were performed. Quade’s rank of covariance was used to explore group differences while controlling for the age of the autistic child. The same analyses were performed according to the sibling’s diagnostic status (concordant and non-concordant pairs) and the sibling’s sex. For both the comparison based on sibling status or sibling characteristics (e.g., birth order, sex, autism diagnostic status), the subdomain and individual item analyses of the ADI-R were further explored when there was significant score differences between groups in the preceding domain. Our analysis focused on the ADI-R because of its detailed breakdown into subdomains and individual items. By doing so, specific analysis of individual actions and behaviors could be analyzed in greater detail. Post-hoc analyses were conducted to identify specific differences between groups. Pearson correlation was used to explore potential associations between sibling age gap and ADI-R scores. Statistical analyses were performed using IBM SPSS version 26.0 (IBM Corp., Armonk, NY, USA).


Our study included 895 children ranging from 2 to 13 years old, and the majority of participants were male (81.3%). Among the children, 51.0% had siblings, with 37.2% having older siblings, 39.9% having younger siblings, 8.1% being twins, and 14.7% having multiple siblings. Autistic children who had siblings diagnosed with autism were analyzed as a separate subgroup. The participant demographics are presented in Table 1, providing further details.

Demographic characteristics of participants

In terms of the ADOS-2, there were no significant differences in ADOS-2 total CSS, social affect CSS or RRB CSS scores. However, in terms of ADI-R scores, autistic children with siblings scored higher in social interaction domain (F=3.013, p=0.038), while they scored lower in RRB domain (F=4.079, p=0.044). Further subdomain analysis of the RRB domain revealed significant differences in preoccupation and unique interests (F=5.370, p=0.021), as well as routine following (F=4.937, p=0.027) (Table 2) with children with siblings scoring lower than children without siblings.

Clinical scores according to sibling status

When analyzing ADI-R subdomains under the social interaction domain according to sibling birth order, it was found that those with multiple siblings performed better in using nonverbal behaviors compared to those with twin siblings (F=3.791, p=0.005) and when analyzed by items, those with younger siblings performed better in eye contact (F=2.683, p=0.031) and social smiling (F=3.948, p=0.003) compared to twins. Sharing enjoyment abilities were better in those with younger siblings (F=3.473, p=0.008) compared to those with twin siblings. In terms of items, those with younger siblings were best at showing and directing attention (F=5.131, p<0.001). Socioemotional reciprocity was also best seen in those with younger siblings (F=2.458, p=0.044) compared to twin siblings. When analyzing socioemotional reciprocity by breaking it down into items, children with younger siblings were best at using other’s body to communicate (F=4.132, p=0.003) and quality of social overtures (F=4.196, p=0.002). When analyzing communication skills of autistic children, instrumental gesture (F=2.452, p=0.045) were also found to be better in autistic children with younger siblings than those with older siblings (Table 3).

ADI-R domain, subdomain, and item scores according to sibling birth order

When analyzing the data based on the autism spectrum disorder (ASD) diagnostic status of the sibling, it was found that autistic children with siblings who were also autistic scored higher in the social interaction domain (F=8.541, p=0.004). This difference was seen in subdomains such as peer relationships (F=7.458, p=0.006), sharing enjoyment (F=8.625, p=0.003), and socioemotional reciprocity (F=5.458, p=0.020). In the communication domain, probands with autistic siblings showed greater deficits in social imitative play (F=13.463, p<0.001) (Table 4).

ADI-R domain, subdomain, and item scores according to affected status of the sibling

Additional analysis was conducted based on sibling sex and age gap. The scores on the ADI-R, ADOS-2, VABS-II, and SCQ did not differ according to the sex homogeneity of the sibling (Supplementary Table 1 in the online-only Data Supplement). However, a greater age gap with the sibling was negatively correlated with higher scores in the ADI-R social interaction (r=-0.264, p<0.001) and ADI-R verbal communication (r=-0.293, p<0.001) domains (Supplementary Table 2 in the online-only Data Supplement).


This retrospective cohort study aimed to explore the social skills of autistic children according to sibling status and characteristics such as birth order or the affected status of the sibling.

One of the primary findings of this study was that autistic children with siblings showed fewer difficulties RRBs. These findings are consistent with previous studies that have highlighted the positive influence of typically developing siblings on the social communication and social responsiveness of autistic children in various environments, including intervention and natural settings such as home or school [21-23]. Autistic children often lack opportunities to interact with peers, making siblings crucial partners for practicing social skills.

In terms of RRB, RRBs are considered an inherent diagnostic feature of autism, and preoccupations or unique interests are thought to be less influenced by social or environmental factors. However, our study found that autistic children with siblings exhibited fewer RRBs on both evaluation scales of ADI-R and ADOS-2. While the interaction with siblings itself may contribute to reducing these behaviors, it is also possible that a change in parenting style associated with having multiple children could influence how children adhere to routines and schedules. A previous study by Gass et al. [24] revealed that parents who had raised an older typically developing child exhibited lower levels of anxiety in their parenting styles. Stressful or authoritative parenting style have been associated with increased child anxiety, and some studies have suggested a link between higher anxiety levels and more pronounced RRBs [24]. Therefore, considering that parenting style can affect the autistic child’s stress levels, there may be a correlation between parenting style and the severity of RRBs. Furthermore, RRBs not only impact the autistic individual but also require family accommodation behaviors (FAB) [25]. FABs encompass the actions taken by the family to help the autistic child adjust to their environment by implementing routines that assist the child in coping with different situations. FAB often necessitate modifying family plans and interests to support the affected child and require substantial effort from all family members. Such accommodations may pose challenges in families with multiple children, potentially requiring the autistic child to adapt to situations where RRBs cannot be carried out.

When exploring the relationship between specific social skills and sibling birth order, we found that difficulties in nonverbal behaviors were most prevalent in children with twin siblings and least prevalent in children with multiple siblings. For those with younger siblings, it is possible that the close proximity between the social age of autistic child and the chronological age of the younger sibling provided an opportunity for the autistic child to learn from a similar level of social maturity. While for children with older siblings, as one by Ben-Itzchak et al. [10] have also emphasized, older siblings may help in terms of communication and adjustment to socially stressful settings. While having a twin sibling, the unaffected sibling may be much more mature socially, but at the same time may not be mature enough to provide a positive influence as older siblings do. Furthermore, through item analysis it was found that children with younger unaffected siblings showed less deficits in enjoyment sharing and socioemotional reciprocity compared to those with older siblings. However, interestingly, when including the group with no siblings, those with no siblings performed better in nonverbal behavior, enjoyment sharing and socioemotional reciprocity than children with older siblings. This may perhaps be due to greater investment and emotional support given to the only child compared to those with older siblings, indicating that there are multiple children. Further research is suggested in child investment patterns of single versus multiple children families.

The comparison of concordant to non-concordant pairs revealed differences in social interactions and communication, such as sharing enjoyment and social imitation. Sharing enjoyment and imitation require mutual interest, and having a less social sibling may hinder the development of mutual interest by providing fewer opportunities for imitation and practicing sharing enjoyment. These results align with a previous study that highlighted the lack of imitation in pairs of autistic children due to deficits in joint attention [26]. Furthermore, concordant pairs are more likely to be syndromic, where the autistic presentation is caused by a chromosomal abnormality. Autistic children with syndromic autism, such as Fragile X syndrome or tuberous sclerosis, are likely to have other conditions, such as intellectual disability, which further present challenges in developing social skills [27].

In alignment with the findings of the study conducted by Ben-Itzchak et al. [10], the sex of the sibling did not influence the social functioning of the autistic child. A larger age gap was correlated with lower ADI-R scores. However, interpretation of these results should be done with caution as we did not analyze the age gap according to the birth order of the sibling. For instance, when the age gap of the autistic child and sibling is smaller, both participants are expected to be at similar level of development and so when the autistic child shows delay in development, this difference could be exaggerated due to direct comparisons in parental reports. On the other hand, when the age gap between the autistic child and sibling is larger, the comparison between the two participants may be less pronounced. For future studies, it may be more helpful to analyze the age gap based on to the birth order of siblings.

This study is novel in its approach to exploring multiple sibling characteristics and their effects on social functioning of autistic children, which may pave the way for more individualized sibling-mediated interventions. However, it also has several limitations. First, the study heavily relied on caregiver-reported results, which are susceptible to overestimation or underestimation of their children’s abilities and are prone to recall bias. Secondly, as mentioned earlier, the heterogeneity of the study population necessitates further analysis after classifying them into subgroups based on other traits, such as language ability or comorbidities. Thirdly, a larger sample population would be beneficial to accurately examine the results of concordant sibling pairs. Finally, a longitudinal analysis of the sibling pairs could provide valuable insight into how sibling relationships evolve over time and how these changes influence both the autistic child and their siblings.

This study explored how siblings and four different characteristics of siblings including birth order, affected status, sex, and age gap, are associated with the social functioning and communication skills of autistic children. As hypothesized social skills differed according to sibling status and ASD diagnosis status of the sibling. In addition, as expected social skills did not differ according to the sex of siblings. However, while the study hypothesized children with older siblings to show less deficits in social skills similar to previous studies, in our study, children with younger, older, and multiple siblings displayed better outcomes compared to twin siblings, especially nonverbal behaviors. In terms of age gap, unlike the hypothesis, larger age gap was associated with better results in social skills. This may be due to several reasons, one of which is that the optimal age gap may be different for children of different age ranges. The optimal age gap may be different for children of different age ranges. Nonetheless, the findings suggest that siblings may offer opportunities to enhance social and communication skills in autistic children. Based on these results, we urge clinicians to consider providing more individualized sibling interventions for autistic children, involving their siblings, and encourage researchers to investigate the longterm influences of such interventions.

Supplementary materials

The online-only Data Supplement is available with this article at

Supplementary Table 1.

Sibling sex and ADI-R scores

Supplementary Table 2.

Correlation between age gap and ADI-R scores



Availability of Data and Material

The datasets generated or analyzed during the study are not publicly available as the IRB approved the data to be used within the research team but could be available from the corresponding author on reasonable request.

Conflicts of Interest

The authors have no potential conflicts of interest to disclose.

Author Contributions

Conceptualization: Se Yeon Kim, Hee Jeong Yoo. Data curation: Se Yeon Kim, Da-Yea Song, Hee Jeong Yoo. Formal analysis: Se Yeon Kim, Da-Yea Song, Hee Jeong Yoo. Funding acquisition: Hee Jeong Yoo. Investigation: Se Yeon Kim. Methodology: Se Yeon Kim, Hee Jeong Yoo. Project administration: Hee Jeong Yoo. Resources: Hee Jeong Yoo. Supervision: Hee Jeong Yoo. Validation: Hee Jeong Yoo. Visualization: Se Yeon Kim. Writing—original draft: Se Yeon Kim. Writing—review & editing: Da-Yea Song, Guiyoung Bong, Jae Hyun Han, Hee Jeong Yoo.

Funding Statement

This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF), funded by the Korean government (MSIT) (No. 2021M3E5D9021878).


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Article information Continued

Table 1.

Demographic characteristics of participants

Variable Classification 1
Classification 2
Classification 3
Sibling No sibling p Older Younger Twin Multiple p Autistic Non-autistic p
Total 456 439 - 170 182 37 67 - 37 419 -
Age (mo) 73.91±32.98 65.13±27.14 <0.001 69.51±32.12 79.09±34.01 67.19±31.88 74.69±31.30 <0.027 66.57±27.17 74.55±33.39 0.100
Sex (M/F) 375/81 353/86 0.492 144/26 150/32 27/10 54/13 0.390 27/10 348/71 0.124

Values are presented as mean±standard deviation or number. M, male; F, female

Table 2.

Clinical scores according to sibling status

Variable Sibling (N=456) No sibling (N=439) p F
ADOS-2 total CSS 7.00±1.86 7.05±1.77 0.281 1.166
 Social affect CSS 7.48±1.79 7.40±1.78 0.906 0.014
 RRB CSS 5.62±2.64 6.00±2.41 0.089 2.891
ADI-R social interaction domain 15.01±2.71 14.70±2.11 0.038* 3.013
 Use of nonverbal behaviors 2.42±1.46 2.34±1.36 0.007* 7.346
 Peer relationships 4.64±2.39 4.52±2.12 0.443 0.589
 Shared enjoyment 3.48±1.86 3.38±1.81 0.037* 4.384
 Socioemotional reciprocity 4.50±2.44 4.47±2.19 0.149 2.087
ADI-R communication domain 7.16±4.31 7.83±3.78 0.487 0.483
 Use of gestures 3.68±2.67 4.07±2.56 0.292 1.110
 Play skills 4.03±1.72 4.00±1.52 0.152 2.055
ADI-R RRB domain 5.19±2.61 5.50±2.60 0.044* 4.079
 Circumscribed patterns of interests 1.27±1.09 1.44±1.22 0.021* 5.370
 Adherences to routines or rituals 0.87±1.05 1.03±1.17 0.027* 4.937
 Stereotyped or repetitive motor movements 0.77±0.85 0.82±0.84 0.512 0.429
 Preoccupations with part of objects 1.08±0.75 1.11±0.74 0.783 0.076
VABS-II total scores 65.29±20.94 69.27±20.66 0.002* 9.492
 Communication skills 68.77±21.15 74.36±21.15 <0.001* 14.341
 Socialization skills 60.92±18.29 63.16±16.76 0.024* 5.115
 Daily living skills 73.25±21.24 77.07±18.63 0.002* 2.479
 Motor skills 75.45±15.20 77.87±16.25 0.057 3.628
SCQ current 14.77±7.33 14.41±7.30 0.392 0.734

Values are presented as mean±standard deviation.



ADOS-2, Autism Diagnostic Observation Schedule; CSS, Calibrated Severity Score; ADI-R, Autism Diagnostic Interview-Revised; RRB, repetitive, restricted behaviors; VABS-II, Vineland Adaptive Behavior Scale, Second Edition; SCQ, Social Communication Questionnaire

Table 3.

ADI-R domain, subdomain, and item scores according to sibling birth order

Variable No sibling (N=439) Older (N=170) Younger (N=182) Twin (N=37) Multiple (N=67) p F
ADI-R social interaction domain 14.70±6.21 15.95±6.52 13.85±6.72 17.51±6.35 14.40±6.52 0.003* 4.095
 Use of nonverbal behaviors 2.34±1.34 2.55±1.53 2.25±1.42 3.05±1.33 2.19±1.37 0.005* 3.791
  Eye contact 1.03±0.52 1.18±0.53 1.05±0.59 1.24±0.44 0.95±0.52 0.031 2.683
  Social smile 1.10±0.75 1.19±0.76 1.13±0.83 1.58±0.65 1.12±0.73 0.003* 3.948
  Facial expression 0.73±0.63 0.84±0.67 0.79±0.65 0.92±0.69 0.79±0.62 0.258 1.327
 Peer relationships 4.52±2.12 4.48±2.32 4.41±2.38 5.05±2.71 4.51±2.41 0.211 1.463
 Shared enjoyment 3.38±1.81 3.69±1.91 3.15±1.86 4.24±1.42 3.40±1.73 0.008* 3.473
  Showing and directing attention 1.06±0.86 1.24±0.87 0.92±0.80 1.53±0.65 1.18±0.88 <0.001* 5.131
  Offering to share 1.49±0.71 1.55±0.71 1.44±0.73 1.72±0.62 1.53±0.68 0.106 1.915
  Seeking to share enjoyment with others 0.84±0.74 0.89±0.75 0.83±0.78 1.11±0.67 0.74±0.66 0.193 1.525
 Socioemotional reciprocity 4.47±2.19 4.88±2.48 4.08±2.39 5.16±2.36 4.30±2.33 0.044* 2.458
  Use of other’s body to communicate 0.46±0.66 0.62±0.76 0.30±0.55 0.62±0.79 0.52±0.62 0.003* 4.132
  Offering comfort 1.22±0.67 1.21±0.72 1.03±0.76 1.36±0.59 1.06±0.73 0.267 1.302
  Quality of social overtures 0.71±0.65 0.88±0.73 0.63±0.64 0.94±0.63 0.58±0.73 0.002* 4.196
  Inappropriate facial expressions 0.81±0.74 0.81±0.75 0.93±0.76 0.86±0.76 0.83±0.77 0.703 0.544
  Appropriateness of social responses 1.29±0.73 1.37±0.77 1.24±0.76 1.46±0.69 1.41±0.68 0.177 1.581
ADI-R communication domain 7.83±3.78 7.82±4.22 6.24±4.22 8.49±4.45 7.22±4.30 0.045* 42.450
 Use of gestures 4.07±2.56 4.08±2.74 3.11±2.54 4.51±2.84 3.75±2.67 0.031* 2.672
  Pointing 1.11±0.77 1.13±0.86 0.91±0.81 1.08±0.83 0.97±0.84 0.189 1.537
  Nodding 1.04±0.90 1.04±0.92 0.80±0.90 1.04±0.96 0.95±0.93 0.507 0.829
  Head shaking 0.72±0.86 0.68±0.85 0.47±0.74 0.75±0.85 0.68±0.87 0.094 1.993
  Instrumental gestures 1.21±0.77 1.31±0.75 1.01±0.82 1.33±0.82 1.27±0.76 0.045* 2.452
 Social imitative play 4.00±1.52 4.20±1.63 3.73±1.73 4.33±1.62 4.00±1.70 0.409 0.997

Values are presented as mean±standard deviation.


p<0.05, ANCOVA;

significant differences on post-hoc analysis.

ADI-R, Autism Diagnostic Interview-Revised; ANCOVA, analysis of covariance

Table 4.

ADI-R domain, subdomain, and item scores according to affected status of the sibling

Variable Sibling without ASD (N=407) Sibling with ASD (N=37) p F df
Social interaction domain 14.77±6.61 17.76±6.81 0.004* 8.541 1
 Nonverbal behavior 2.39±1.48 2.68±1.27 0.183 1.775 1
 Peer relationship 4.56±2.37 5.58±2.47 0.006* 7.458 1
  Interest in children 1.94±2.07 2.00±1.60 0.380 4.298 1
  Response to approaches of other children 1.83±2.08 1.83±1.67 0.080 3.076 1
 Shared enjoyment 3.41±1.85 4.24±1.71 0.003* 8.625 1
  Showing and directing attention 1.08±0.87 1.50±0.81 0.003* 8.667 1
  Offering to share 1.49±0.71 1.78±0.54 0.011* 6.456 1
  Seeking to share enjoyment with others 0.84±0.74 1.08±0.81 0.074 3.194 1
  Socioemotional reciprocity 4.42±2.41 5.41±2.62 0.020* 5.458 1
  Use of other’s body to communicate 0.46±0.66 0.64±0.83 0.307 1.046 1
  Offering comfort 1.17±0.71 1.25±0.69 0.566 0.330 1
  Quality of social overtures 0.72±0.67 0.92±0.73 0.108 2.592 1
  Inappropriate facial expressions 0.82±0.74 1.25±0.73 0.001* 11.539 1
  Appropriateness of social responses 1.31±0.74 1.50±0.61 0.173 1.856 1
Communication Domain 6.99±4.31 9.05±3.98 0.013* 6.218 1
 Gesture 3.59±2.69 3.59±2.62 0.074 3.299 1
 Social imitative play 3.94±1.73 4.94±1.35 <0.001* 13.463 1
 Spontaneous imitation of actions 1.42±0.73 1.71±0.62 0.011* 6.536 1
 Imaginative play 1.47±0.67 1.83±0.45 0.001* 12.103 1

Values are presented as mean±standard deviation.


p<0.05, ANCOVA.

ADI-R, Autism Diagnostic Interview-Revised; ASD, autism spectrum disorder; ANCOVA, analysis of covariance