Astudyreports that while about 50% of the population with autism spectrum disorder (ASD) have intellectual disability (ID), people with ID -defined as having IQ below 70- are extremely under-included across all fields of autism research. This is an example of selection bias. The authors explain that selection bias in intellectual disability studies may occur because people with more severe difficulties are harder to recruit and retain in research studies and that families of children with ID are harder to recruit as they may have less time and resources.

What could be the implications of this selection bias for people with ID? Can you think of ways to mitigate the problem?