According to IDEA, Intellectual and Developmental Disabilities are defined as:

According to IDEA, Intellectual and Developmental Disabilities are defined as:

• A. Significantly subaverage general intellectual functioning with deficits in adaptive behavior manifesting during the developmental period and adversely affecting educational performance.
• B. A learning disability caused by environmental factors affecting academic performance.
• C. A temporary delay in reaching developmental milestones without affecting adaptive skills.
• D. A sensory impairment that does not impact adaptive behavior.

Answer: (A)

Intellectual and developmental disabilities, as defined by IDEA, involve significantly subaverage general intellectual functioning with deficits in adaptive behavior that emerge during the developmental period and that adversely affect educational performance. This means a noticeable gap in overall thinking abilities paired with real-world skills needed for daily life—conceptual, social, and practical skills. Importantly, these challenges begin in childhood or adolescence, and together they lead to difficulties in learning and school performance, which is why supports and services under IDEA are appropriate. The other descriptions don’t fit this definition. A learning disability typically refers to difficulties with specific cognitive processes affecting academic tasks, not a broad picture of intellectual functioning plus adaptive-skill deficits. A temporary delay in reaching milestones without adaptive skill impact doesn’t meet the requirement of deficits in adaptive behavior. A sensory impairment that doesn’t affect adaptive behavior also fails to capture the broader functional and developmental timing that IDEA uses to define these disabilities.

Intellectual and developmental disabilities, as defined by IDEA, involve significantly subaverage general intellectual functioning with deficits in adaptive behavior that emerge during the developmental period and that adversely affect educational performance. This means a noticeable gap in overall thinking abilities paired with real-world skills needed for daily life—conceptual, social, and practical skills. Importantly, these challenges begin in childhood or adolescence, and together they lead to difficulties in learning and school performance, which is why supports and services under IDEA are appropriate.

The other descriptions don’t fit this definition. A learning disability typically refers to difficulties with specific cognitive processes affecting academic tasks, not a broad picture of intellectual functioning plus adaptive-skill deficits. A temporary delay in reaching milestones without adaptive skill impact doesn’t meet the requirement of deficits in adaptive behavior. A sensory impairment that doesn’t affect adaptive behavior also fails to capture the broader functional and developmental timing that IDEA uses to define these disabilities.