Autism Symptom Presentation and Hierarchical Models of Intelligence

Area of Science:

• Neurodevelopmental disorders
• Cognitive psychology
• Psychometrics

Background:

• Research has explored general intelligence and autism core symptoms.
• A knowledge gap exists regarding how autism symptomatology relates to hierarchical intelligence models.

Purpose of the Study:

• To investigate the association between autism diagnostic symptom severity and a hierarchical intelligence model.
• To compare findings across different versions of the Wechsler Intelligence Scale for Children (WISC).

Main Methods:

• Correlations were analyzed between Autism Diagnostic Observational Schedule (ADOS) scores and intelligence factors.
• Two cohorts of autistic individuals were tested using either the WISC-IV (N=131) or WISC-V (N=83).

Main Results:

• WISC-IV: ADOS scores significantly correlated with general intelligence (g) and three of four intermediate factors.
• WISC-V: Only one intermediate factor showed a significant correlation with ADOS; correlations with g and other factors were less certain.
• Correlations between ADOS and intelligence factors were stronger in the WISC-IV cohort compared to the WISC-V cohort.

Conclusions:

• The WISC-IV demonstrates dimensional relationships with ADOS across multiple intelligence levels.
• The association between autism symptoms and general intelligence may be influenced by the specific IQ measurement tool.
• This study provides initial evidence that different IQ test versions, not just diagnostic practices, may explain cohort effects in autism research.