SLK 310 Chapter 5
Erin Polyblank
Chapter 5- Intellectual disability
(Intellectual developmental
disorder)
Intelligence and intellectual disability
The Eugenics scare
Evolutionary degeneracy theory attributed the intellectual and social
problems of children with intellectual disability to regression to an earlier
period in human evolution.
J. Langdon H. Down, best known for the clinical description of the genetic
syndrome that bears his name, interpreted the "strange anomalies" among
his medical sample of persons with intellectual disability as an evolutionary
throwback to the Mongol race.
o Down believed that parents in one racial group might give birth to a child
with intellectual disability who was a "retrogression" to another group.
Eugenics was first defined by Sir Francis Galton in 1883.
o Eugenics: The science which deals with all influences that improve the
inborn qualities of a race".
By 1910 the eugenics movement was gaining popularity.
o Public and professional emphasis shifted away from the needs of persons
with intellectual disability toward a consideration of the needs of society;
society was to be protected from the presumable harm done by the
presence of these persons in the community.
Persons with intellectual disability often were blamed for the social ills of the
time, which is a powerful example of how labelling a problem can quickly
become an explanation for it.
o The appearance, ability, and behaviour of persons with intellectual
disability were considered evidence of their lack of moral fibre, a belief
that led to the diagnostic term moral imbecile, or moron, used to describe
and explain their differences.
This concept became a straightforward explanation for acts of
deviance and justified wide-ranging attempts to identify and control
such individuals.
1
,SLK 310 Chapter 5
Erin Polyblank
o “Morons”, were seen as a threat to society because, unlike the insane,
they could easily pass for normal.
The intellectually impaired and other "undesirables" were seen as a
public menace, to be feared and ostracized.
Defining and measuring children’s intelligence and adaptive behaviour
Alfred Binet and Theophile Simon, were asked to develop a way to identify
schoolchildren who might need special help in school.
o They developed the first intelligence tests to measure judgment and
reasoning.
They believed these were basic processes of higher thought.
Early test questions asked children to manipulate unfamiliar objects such as
blocks or figures and to solve puzzles and match familiar parts of objects.
o The test later became the Stanford-Binet scale, which remains one of the
most widely used intelligence tests.
General intellectual functioning is now defined by an intelligence quotient
(IQ or equivalent) that is based on assessment with one or more of the
standardized, individually administered intelligence tests, such as the
Wechsler Intelligence Scales for Children, the Stanford-Binet, and the
Kaufman Assessment Battery for Children.
o These tests assess various verbal and visual-spatial skills and
mathematical concepts, which together are presumed to constitute the
general construct known as "intelligence."
By convention, IQ scores (with a mean of 100 and a standard deviation of 15)
are derived from a standardized table based on a person's age and test score.
o Because intelligence is defined along a normal distribution, approximately
95% of the population has scores within 2 standard deviations of the
mean (i.e., between 70 and 130).
o Subaverage intellectual functioning is defined, accordingly, as an IQ of
about 70 or below (approximately 2 standard deviations below the mean).
The definition of intellectual disability includes not only subaverage
intellectual functioning, but also a subaverage level of adaptive functioning.
o Adaptive functioning: How effectively individuals cope with ordinary
life demands, and how capable they are of living independently and
abiding by community standards.
2
, SLK 310 Chapter 5
Erin Polyblank
Some children and adolescents may learn to adapt quite well to their
environment despite their lower intelligence as measured by an IQ test;
therefore, they would not be considered to have an intellectual disability.
3 major categories of adaptive behaviour:
1. Conceptual skills
Receptive and expressive language
Reading and writing
Money concepts
Self-directions
2. Social skills
Interpersonal Responsibility
Self-esteem
Gullibility (likelihood of being tricked or manipulated)
Naiveté
Follows rules
Obeys laws
Avoids victimization
3. Practical skills
Personal activities of daily living such as eating, dressing, mobility, and
toileting.
Instrumental activities of daily living such as preparing meals, taking
medication, using the telephone, managing money, using transportation,
and doing housekeeping activities.
The controversial IQ
If a person’s intelligence is relatively stable over time, it would be tempting to
conclude that it is fixed or innate.
o Although, if intellectual and cognitive development is significantly shaped
by environment, perhaps cognitive growth can be stimulated at an early
age and the level of intellectual disability decreased.
3
Erin Polyblank
Chapter 5- Intellectual disability
(Intellectual developmental
disorder)
Intelligence and intellectual disability
The Eugenics scare
Evolutionary degeneracy theory attributed the intellectual and social
problems of children with intellectual disability to regression to an earlier
period in human evolution.
J. Langdon H. Down, best known for the clinical description of the genetic
syndrome that bears his name, interpreted the "strange anomalies" among
his medical sample of persons with intellectual disability as an evolutionary
throwback to the Mongol race.
o Down believed that parents in one racial group might give birth to a child
with intellectual disability who was a "retrogression" to another group.
Eugenics was first defined by Sir Francis Galton in 1883.
o Eugenics: The science which deals with all influences that improve the
inborn qualities of a race".
By 1910 the eugenics movement was gaining popularity.
o Public and professional emphasis shifted away from the needs of persons
with intellectual disability toward a consideration of the needs of society;
society was to be protected from the presumable harm done by the
presence of these persons in the community.
Persons with intellectual disability often were blamed for the social ills of the
time, which is a powerful example of how labelling a problem can quickly
become an explanation for it.
o The appearance, ability, and behaviour of persons with intellectual
disability were considered evidence of their lack of moral fibre, a belief
that led to the diagnostic term moral imbecile, or moron, used to describe
and explain their differences.
This concept became a straightforward explanation for acts of
deviance and justified wide-ranging attempts to identify and control
such individuals.
1
,SLK 310 Chapter 5
Erin Polyblank
o “Morons”, were seen as a threat to society because, unlike the insane,
they could easily pass for normal.
The intellectually impaired and other "undesirables" were seen as a
public menace, to be feared and ostracized.
Defining and measuring children’s intelligence and adaptive behaviour
Alfred Binet and Theophile Simon, were asked to develop a way to identify
schoolchildren who might need special help in school.
o They developed the first intelligence tests to measure judgment and
reasoning.
They believed these were basic processes of higher thought.
Early test questions asked children to manipulate unfamiliar objects such as
blocks or figures and to solve puzzles and match familiar parts of objects.
o The test later became the Stanford-Binet scale, which remains one of the
most widely used intelligence tests.
General intellectual functioning is now defined by an intelligence quotient
(IQ or equivalent) that is based on assessment with one or more of the
standardized, individually administered intelligence tests, such as the
Wechsler Intelligence Scales for Children, the Stanford-Binet, and the
Kaufman Assessment Battery for Children.
o These tests assess various verbal and visual-spatial skills and
mathematical concepts, which together are presumed to constitute the
general construct known as "intelligence."
By convention, IQ scores (with a mean of 100 and a standard deviation of 15)
are derived from a standardized table based on a person's age and test score.
o Because intelligence is defined along a normal distribution, approximately
95% of the population has scores within 2 standard deviations of the
mean (i.e., between 70 and 130).
o Subaverage intellectual functioning is defined, accordingly, as an IQ of
about 70 or below (approximately 2 standard deviations below the mean).
The definition of intellectual disability includes not only subaverage
intellectual functioning, but also a subaverage level of adaptive functioning.
o Adaptive functioning: How effectively individuals cope with ordinary
life demands, and how capable they are of living independently and
abiding by community standards.
2
, SLK 310 Chapter 5
Erin Polyblank
Some children and adolescents may learn to adapt quite well to their
environment despite their lower intelligence as measured by an IQ test;
therefore, they would not be considered to have an intellectual disability.
3 major categories of adaptive behaviour:
1. Conceptual skills
Receptive and expressive language
Reading and writing
Money concepts
Self-directions
2. Social skills
Interpersonal Responsibility
Self-esteem
Gullibility (likelihood of being tricked or manipulated)
Naiveté
Follows rules
Obeys laws
Avoids victimization
3. Practical skills
Personal activities of daily living such as eating, dressing, mobility, and
toileting.
Instrumental activities of daily living such as preparing meals, taking
medication, using the telephone, managing money, using transportation,
and doing housekeeping activities.
The controversial IQ
If a person’s intelligence is relatively stable over time, it would be tempting to
conclude that it is fixed or innate.
o Although, if intellectual and cognitive development is significantly shaped
by environment, perhaps cognitive growth can be stimulated at an early
age and the level of intellectual disability decreased.
3
