1.
Intellectual Disability
What do numbers tell us?
Olaf Kraus de Camargo

2.
Disclaimer
I am not a psychologist!
No conflicts of interest to declare

3.
Numbers & Sizes
What’s your shoe
size?

4.
Numbers & Sizes
What’s your IQ?

5.
Intelligence
§ “...the aggregate or global capacity of the individual to act purposefully, to
think rationally, and to deal effectively with his (or her) environment.”
(Wechsler, 1939)
§ “the ability to solve problems”
https://myfirstapp.com/wp-content/uploads/2020/11/Problem-solving.jpg

6.
Intellectual Disability
• Deficits in intellectual functioning
• Deficits in adaptive functioning
• These limitations occur during the developmental period
(difference to Neurocognitive Disorder)
DSM-V criteria:
Difference to DSM IV: no longer different
codes according to IQ level!

7.
Mental abilities
§ Reasoning
§ Problem solving
§ Planning
§ Abstract thinking
§ Judgement
§ Academic Learning (ability to learn in school)
§ Experiential Learning (ability to learn through experience, trial and
error, and observation)
Weiss, L. G., Holdnack, J. A., Saklofske, D. H., & Prifitera, A. (2019). Theoretical and Clinical Foundations of the
Wechsler Intelligence Scale for Children—Fifth Edition. In Wisc-V (pp. 97-128). https://doi.org/10.1016/b978-
0-12-815744-2.00004-5

8.
Assessment
Ng, 2018 Developmental Pediatrics and Rehabilitation, RJCHC

9.
Assessment
Ng, 2018 Developmental Pediatrics and Rehabilitation, RJCHC

10.
Assessment
Ng, 2018 Developmental Pediatrics and Rehabilitation, RJCHC

11.
Numbers & Sizes

12.
Normal Distribution

13.
Scores
§Results are expressed in different types of scales, depending on
the test being used:
§ Intelligence Quotient: Developmental age x 100/Chronological age
§ Standard Score (100, 120, 80)
§ Percentile Rank (50, 91, 9)
§ T-Score (50, 63, 37)
§ Z-Score (0, +1.33, -1.33)
§ Descriptions (average, high average, superior, very superior, low average,
inferior, borderline, impaired, mild, moderate, severe, profound)

14.
Profiles
Analyzing the profile
allows to identify
strengths and weaknesses

15.
Conversion Table

16.
Psychometric assessment
• Understand strengths and weaknesses for
learning
• Understand level of communication skills
• Understand challenging behaviours
Indications:
• Motivation
• Environment
• Cultural background
Considerations:

17.
Recommendations

18.
Evidence-based Recommendations
ASD ID

19.
Utility
• Ethical aspects
• What is the benefit the child and the family will gain from the results?
• What harm could be caused to a child and the family from the results?
• Recommendations
• Identify strengths that can be used (e.g., strong visual memory)
• Suggest accommodations (e.g., time, educational assistance, technology)
• Only order an assessment if there is a willingness to use the results
in a supportive way to child and family (Rights-based approach)

20.
Rights of Children

21.
Q & A Session
Q A
&
ThankYou!

22.
Contact Us
canchild.ca
@canchild_ca
905.525.9140 x27850
facebook.com/canchild.ca
canchild@mcmaster.ca
Institute for Applied Health
Sciences, McMaster University
1400 Main Street W., Room 408
Hamilton, ON, Canada