Ask the expert


Cognitive Testing


My child is 1½ years old and has CdLS. Are there tests available to determine his level of mental retardation?

Answer of our experts

There are two points to be made regarding cognitive testing. First, tests of intelligence or cognitive functioning are rarely standardized below two years of age. The reliability of these instruments is low and they do not predict future functioning to any degree of accuracy. The experienced psychologist would not attempt such an assessment. However, instruments of developmental functioning are often used and are criterion referenced, not standardized with age norms and standard scores. Adaptive levels of behavior in the areas of communication, daily living skills, socialization and motor skills are available down to birth, but they are not standardized on a population of children with CdLS. Instead, they use a normative sample of the overall population. The second point is that the question of mental retardation should not be addressed until after the child turns 6 years of age or older. Mental retardation is a developmental disability and experience has shown us that to attempt to diagnose it at an early age precludes the opportunity of showing the positive affects on development when enriched learning environments, teaching to specific skill acquisition, and remedial therapies are available and provided. School systems and early intervention programs typically will utilize the descriptor of developmental delay instead of mental retardation for young children  and rightly so.

It is encouraging to witness the availability of non-language and fine motor-free instruments of intelligence that are available to be used with young children who have CdLS or other disabilities, roughly starting at age 4 or 5. These instrument need to be used with caution and great care, of course.

JM/TK 7-13-10

Some other considerations in regard to assessment: The choice of instruments for developmental or cognitive testing must consider the type(s) of disabilities the child is exhibiting. For example, most early developmental assessments use tools that rely on sensory-motor behaviors. Some of these tools may be inappropriate for a young child with severe motor disabilities, blindness and a hearing impairment. Others may be more appropriate. Thus, the selection of the tool is important. Secondly, a one time observation may or may not be representational of overall functional behaviors. The examiner needs to be cautious in regard to making judgments based on one exposure. Lastly, consideration must be given in HOW the results are interpreted. For example, if an examiner has no experience in assessing children who are blind, then the behaviors observed are at high risk for misinterpretation, if the child has severe visual defects.

A valuable type of testing is to examine the child's functional behaviors, during normal routines, within the familiar environment AND to document these behaviors with video vignettes. Subsequent functional video vignettes help to document both quantitative and qualitative changes over time with the child being compared to him/herself. The most valuable tapes, for comparison purposes, video the same type of activities every 3 to 4 months with the each tape session lasting no longer than 45 minutes. MM/ TK 7-13-10

Answer is checked and valid for
Find other pages that share the same topic as this page Intellectual Disability3 Intellectual Disability5

Legal Disclaimer

Please take note that the Ask the Expert service is comprised of volunteer professionals in various areas of focus. Answers are not considered a medical, behavioral, or educational consultation. Ask the Expert is not a substitute for the care and attention your child’s personal physician, psychologist, educational consultant, or social worker can deliver.

Do you have a question you would like to ask?

Ask a Question

Do You urgently need help? Contact the CdLS Foundation USA, Our Staff!