Autism vs. Intellectual Disability: Understanding Key Differences in Developmental Testing
Understanding the Overlap
Parents often wonder whether their child’s developmental differences are related to autism spectrum disorder (ASD), intellectual disability (ID), or both. The confusion is understandable — these conditions can appear similar in early childhood.
Both autism and intellectual disability can involve communication delays, social challenges, and learning differences. However, they represent distinct conditions that require different types of support, interventions, and educational planning.
At the Utah Center for Psychological Services in Salt Lake City, our clinicians specialize in comprehensive developmental testing that helps families and providers understand each child’s unique profile — beyond labels or surface-level symptoms.
Defining Autism Spectrum Disorder (ASD)
Autism spectrum disorder is a neurodevelopmental condition characterized by challenges in social communication and interaction and by restricted or repetitive behaviors or interests.
According to the Centers for Disease Control and Prevention (CDC), autism affects approximately 1 in 36 children in the U.S. Signs can include:
Limited eye contact or difficulty understanding social cues
Repetitive behaviors or intense interests
Resistance to changes in routine
Sensory sensitivities (e.g., to sounds, textures, or lights)
Difficulty initiating or maintaining conversations
Importantly, autism does not inherently mean low intelligence. Many children and adults on the autism spectrum have average or above-average cognitive abilities, though they may still need support with social understanding and emotional regulation.
Defining Intellectual Disability (ID)
Intellectual disability involves significant limitations in intellectual functioning (reasoning, problem-solving, learning) and adaptive behavior (daily living, communication, social skills).
According to the American Association on Intellectual and Developmental Disabilities (AAIDD), diagnosis typically requires:
IQ score approximately 70 or below,
Deficits in adaptive functioning, and
Onset during the developmental period (childhood or adolescence).
While autism focuses on differences in social communication and flexibility, intellectual disability reflects a global impact on learning and daily functioning.
Can a Child Have Both Autism and Intellectual Disability?
Yes — some children meet criteria for both conditions. In fact, the National Institutes of Health reports that up to one-third of individuals with autism also have intellectual disability.
When both are present, a child may show:
Delays across multiple areas of learning and reasoning
Significant language impairment
Challenges with adaptive and self-care skills
Limited social engagement or repetitive interests
Comprehensive evaluation helps clarify whether observed behaviors are due to general cognitive delay, autistic traits, or both. This distinction shapes the best plan for therapies, education, and community supports.
How Developmental Testing Helps Differentiate ASD and ID
At our clinic, developmental and psychological evaluations are tailored to the child’s communication style, attention span, and strengths. These assessments may include:
Cognitive testing: Measures reasoning, problem-solving, and processing abilities.
Adaptive functioning measures: Evaluate independence in communication, socialization, and daily living.
Autism-specific assessments: Tools such as the ADOS-2 (Autism Diagnostic Observation Schedule, Second Edition) and ADI-R (Autism Diagnostic Interview-Revised).
Language and social-emotional tests: To assess understanding, expression, and play skills.
Parent and teacher questionnaires: Capture real-world functioning across settings.
Our psychologists integrate these results to determine whether a child’s profile reflects autism, intellectual disability, or another neurodevelopmental pattern.
Why Accurate Diagnosis Matters
While both autism and intellectual disability may qualify a child for educational or therapeutic services, the types of supports that are most helpful can be quite different.
For children with autism spectrum disorder, the primary needs often involve improving social communication, flexibility, and sensory regulation. Helpful interventions may include speech therapy, social skills groups, behavioral therapy (such as ABA), and occupational therapy for sensory processing.
For children with intellectual disability, the focus is usually on academic and adaptive skill development—including daily living, safety awareness, and independence. These children may benefit most from specialized education programs, adaptive behavior therapy, and caregiver coaching.
For children who have both autism and intellectual disability, a combination of these approaches is needed. These children often thrive when they receive individualized, interdisciplinary support that integrates communication, cognitive, and behavioral interventions across home, school, and therapy settings.
Getting an accurate diagnosis ensures that every child receives the right level of support and that interventions are targeted to their unique profile—helping families and schools focus on what will truly make a difference.
Family Education and Collaboration
At the Utah Center for Psychological Services, we believe parents should leave every evaluation with not just answers, but understanding. We take time to:
Explain test findings in plain language
Identify actionable steps for home and school
Connect families with community resources such as Autism Speaks and The Arc of Utah
We also collaborate with pediatricians, speech-language pathologists, and educators to ensure recommendations translate into effective, everyday supports.
Seeing Beyond the Label
Every child — regardless of diagnosis — deserves to be seen as a whole person with potential, preferences, and personality. Labels like “autism” or “intellectual disability” are starting points, not definitions of who a child can become.
Our evaluations aim to illuminate strengths and guide a plan for growth, self-advocacy, and independence.
Take the Next Step
If you’re seeking clarity about your child’s development, we’re here to help. The Utah Center for Psychological Services in Salt Lake City provides comprehensive developmental evaluations to help distinguish autism, intellectual disability, and related conditions.
For more information about developmental milestones and neurodiversity, visit the CDC’s “Learn the Signs. Act Early.” page.
