1. Chapter 11 pt. 2: Intelligence Assessment

2. Assessing Intelligence: Aptitude vs. Achievement Test
Aptitude Tests: are tests designed to predict a person’s future performance.
SAT’s and GRE’s
Achievement Test: a test designed to assess what a person has learned.
Midterm Psych exam, chapter 3 history test, etc.

3. Assessing Intelligence
Wechsler Adult Intelligence Scale (WAIS)
most widely used intelligence test
subtests
verbal
performance (nonverbal)
Also a WISC (Wechsler Intelligence Test for Children).

4. Assessing Intelligence- Sample Items from the WAIS
VERBAL
General Information
Similarities
Arithmetic Reasoning
Vocabulary
Comprehension
Digit Span
PERFORMANCE
Picture Completion
Picture Arrangement
Block Design
Object Assembly
Digit-Symbol Substitution

5. WAIS SAMPLE

7. Qualities of A Good Test
To be accepted all psychological tests must be:
Standardized
Reliable
Valid

8. Standardization
Standardization: defining meaningful scores by comparison with the performance of a pretested group.
Your scores are compared with the pretested group who took the test.
Standardized tests usually follow a normal distribution.
Normal Distribution: bell shaped curve that describes the distribution of many physical and psychological properties. Most scores fall near average, and fewer and fewer scores lie near the extreme.

9. The Normal Curve (Know My Distributions)
Ninety-five percent
of all people fall
within 30 points
of 100
Number of scores
Wechsler intelligence score
Sixty-eight percent
of people score
within 15 points
above or below 100

10. Reliability vs. Validity (DON’T MIX THEM UP)
Reliability deals with consistency. assessed by consistency of scores on:
two halves of the test
alternate forms of the test
retesting the same individual
Weschler and Standford Binet test +.9
Validity deals with predictability. Does the test measure what it is supposed to measure?

11. Types of Validity
Content Validity: the extent to which a test samples the behavior that is of interest.Would a maneuverability test on a skateboard have content validity for testing to see if your qualified to drive?
Predictive Validity: The success with which a test predicts the behavior it is supposed to predict.
Do high SAT scores correlate with high college grades?

12. Predictive Validity is Based on Criterion
Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful.
What would the criterion be for the GRE’s?

13. The Flynn Effect
Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect).
If standardized with today’s tests, scores 80 years ago would have a average IQ of 76.
Possible Causes?

14. The Flynn Effect

15. Stability of Change? Can infant tests predict future intelligence?
Picture Test
Starting at Age 4 may predict future IQ
Age 7 scores become stable,but not fixed

16. Low Extreme of Intelligence
Intellectual disability: condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life.

17. Low Extreme of Intelligence
Down Syndrome: condition of intellectual disability and associated physical disorders caused by an extra chromosome in one’s genetic makeup.
Many people with Down Syndrome can adapt to disorder and some have earned college degrees with accomodations…nearly all learn how to read.

18. Degrees of Intellectual Disability
Degrees of Mental Retardation
Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life
Mild % Most learn academic skills up to
sixth-grade level. Adults may, with
assistance, achieve self-supporting
social and vocational skills.
Moderate May progress to second-grade level.
academically. Adults may contribute
to their own support by labor in
sheltered workshops.
Severe May learn to talk and perform simple
work tasks under close supervision
but are generally unable to profit from
vocational training.

19. Gifted Smart kids are usually not “weird” Tend to get higher degrees
Should gifted children be “tracked” in school?

20. Is Intelligence Genetic or Environmental?
Influenced by both, but the most genetically similar have the most similar scores.
Similarity of
intelligence
scores
(correlation)
Identical
twins
reared
together
apart
Fraternal
Siblings
Unrelated
individuals

21. Genetic Influences With age, genetic influences become more apparent.
Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age.
Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability).

22. Genetic Influences 0.35 0.30 Child-parent 0.25 correlation in
0.20
0.15
0.10
0.05
0.00
3 years years
Child-parent
correlation in
verbal ability
scores
Children and their
birth parents
Adopted children
and their birth
parents
and their adoptive

23. Environmental Influences
Early Intervention
Head Start
Schooling Effects
Schooling and IQ scores tend to correlate

24. Schooling Effect IQ gains relative to grade 4 baseline Age in months
Age in months
118
115
112
109
106
103
100 97
IQ gains relative
to grade 4
baseline

25. Group Differences in IQ Scores
Ethnic Similarities and Differences
Racial groups differ in IQ scores
Higher scoring ppl and groups tend to have higher incomes and education
Individual differences within a race are much greater than differences between races
Asian students outperform North American student on math tests
IQ scores have increased
White and blacks tend to score the same on infant IQ tests

26. Variation within group Difference within group
Group Differences in Intelligence Scores Are Probably Mostly Attributed to the Environment
Variation within group
Difference within group
Poor soil
Fertile soil
Seeds

27. Group Differences in IQ Scores
Gender Similarities and Differences
No big differences
Girls are better spellers, more verbal, more sensitive to senses
Boys tend to be in lower classes more and talk later and stutter more
Math and Spatial Aptitudes
No huge differences
Boys tend to do a bit better on math
Girls better on memory and picture recognition
Women better at reading facial expressions

28. The Question of Bias 2 definitions
1. Tests detect not only innate differences in IQ but also differences caused by cultural experiences
Yes. Test do not account for differences in cultures, which may make them bias
2. Is a test less valid for some groups than for others.
No. The predictive value of a standard IQ testS is roughly the same for black and whites and rich and poor…….

29. The Question of Bias
Stereotype Threat
A self confirming concern that one will be evaluated based on a negative stereotype
Black student's taking verbal test
Women and math scores