Lecture 6 (DN) almost done! Flashcards
Group IQ scores are stable over time, does that mean that Individual’s IQ within that group are also stable?
No
What could group stability of IQ scores over time be telling us?
- could suggest good predictive validity of IQ tests
or
- could in fact be indicative of stability of environment over time
- e.g., low SES when 4 likely to be low SES at 14
- regardless of the reason for group stability of IQ stores - the IQ tests are in fact tapping into it
In what way may children be affected by
Family structure, Poor home conditions, Change in parents SES, Adoption, Severe illness
and/or
Therapeutic, remedial, educational/counselling programmes
- These factors may positively or negatively impact children’s intellectual development
- IMPT - absolutely at the Group Level
- does not mean all children are impacted in the same way
- e.g., Californian Guidance Study (n = 222)
- 9% children increased by >30 IQ points
What kind of evidence exists for Instability of Individual IQ Scores within groups over time?
- Group test-retest - high correlation
- but huge individual differences
- 9% in IQ >30 points
- 37% inc IQ > 20 points
- 50% inc IQ > 15 points
- California Guidance Study (n=222)
9:09
Why is it helpful to look at studies such as the California Guidance Study?
- These findings enable us to look at why individuals increase IQ
- e.g., enriched schooling
- Then apply this knowledge to help others to do the same
10:00
If the correlation between a group of 2001 & 2011 IQ scores was high; r = .76,
does this mean an individual’s IQ score in 2001 was predictive of the 2011 IQ score?
- No
- High group correlation from 2001 to 2011 is a very different concept to an individual with the same scores (in 2001 & 2011)
- The correlation only tells you that the variance in the group reamined the same
- e.g., all of the group may go up so the variance (correlation) will be the same.
11:35
What kind of studies have demonstrated a difference between IQ of low compared to high socioeconomic groups?
What is this difference?
- Longitudinal
- Over time
- low SES IQ’s decline
- high SES IQ’s increase
14:40
What did Capron & Duyme do in their 1989 study to demonstrate instability/stability in Individual’s IQ?
- Looked at impact of enriched environments on children’s IQ over time
- 2 x 2 design
- compared high/low SES
- biological with
- adopted
- FOUND
- high SES increased IQ for both groups
Which study looked at the risk factors of a child having a decrease in IQ?
What were the 10 risk factors?
- Rochester Longitudinal Study
- Sameroff et al., (1987, 1993).
- Mother - history of mental illness
- Mother - did not go to high school
- Mother - severe anxiety
- Mother - rigid attitudes
- Few mother-child interactions
- Head of household in a semi-skilled job
- > 4 siblings (greater)
- Father not living at home
- Child belongs to a minority group
- Family had > 20 stressful events in child’s 1st 4 years (greater)
15:00
How many of the 10 risk factors indicated a child was at risk for decreased IQ?
four
What was an assumption of the Rochester Longitudinal Study?
- The greater the number of risk factors present would lead to a greater negative impact on IQ
- 4 risk factors at age 4 reflected decrease IQ and same pattern at follow up age 13
- consider Nature vs Nurture here
15:40
What is the main danger with relation to Group & Individual Differences in IQ measurement?
- The way the data is interpreted
Who is given an IQ score of 100 on the WAIS?
those falling in the 50th percentile
How is the deviation IQ standardised?
according to norms as a funcrtion of age group?
in nine age groups from 16-64 on adult scales
- Mean = 100 / SD = 15
- 1SD above = 115
- 1SD below = 85
What proportion of people will fall within 15 points above or below 100 (i.e., 1SD above or below)?
- 68%
- remember this is stratified for age group
What proportion of people will fall within 30 points above or below 100 (i.e., 2SD’s above or below)?
- 96%
What do cross-sectional studies of age-related changes of IQ enable us to do?
- it enables us to look at age as a continous scale
- even though IQ is standardised by age
- keeping in mind that age related differences may reflect cohort differences
What could age related changes in a cross-sectional analysis reflect?
- fluid vs. crystallised intelligence
- Fluid
- matrices mid 30’s drop off
- Crystalised
- vocabulary mid 60’s drop off
- e.g., Wang & Kaufman, 1993
Why do IQ scores look worse (i.e., take a huge decline with age) when looking at Cross-Sectional compared to Longitudinal Findings?
- Huge cohort effects
- confounded by environment
- not fair to compare a 70 year old with a 20 year old now
- One generation ago there were many changes
- accessibility of information, university, laptops etc
- Clare toddled off to the library & took 4 hours to find one piece of information!!!
26:00
Do the findings of Wang & Kaufman (1993) suggest that age results in a decreased IQ?
- No
- because IQ scores are standardised
- IQ should be relatively stable as it is a refelction of the age group
- there may be a decrease in Intellectual Ability but not IQ
24:30
What does a Cross-Sequential design enable us to do?
- remove variance due to cohort
- & just look at actual differences in IQ ability
Which cognitive ability takes the biggest hit as a function of age?
- Perceptual processing speed
- which also negatively impacts speeded tests
What do cross-sectional studies overestimate?
- overestimate decline in intellectual ability prior to age 60
- e.g., Seattle Longitudinal Study showed this
41:15
What individual differences are protective factors against age related decline, as shown in the Seattle Longitudinal Study
- (a) absence of cardiovascular disease
- (b) favorable environment/High SES
- (c) intellectually stimulating environment
- (d) flexible personality
- (e) high cognitive status of spouse
- (f) maintenance of high processing speeds
Cognitive training - 2/3 sample improved intellectual ability
What is The Flynn Effect?
- Looks at the change in IQ as a function of time
- IQ increases by 3 points every decade
- cohort effects (environmental changes)
- can’t compare 20yr old today with 20 year old years ago
- need to constantly re-norm scores
What ar the main psychometric issue of the Bell Curve Controversy?
- took finding within group & then used it to argue a point between groups
- environments differed between groups
- thus conclusions problematic
- issue was in the interpretation of the data
Jensen (1969) - said Black population had fewer high IQ genes (spinners!!!)
1:19:40
Name a population at-risk for low IQ & legal complications?
What are some implications?
- Indigenous populations
- Intellectually disabled
Implications
- Low IQ - significant factor for criminal offending & reoffending
Why is it difficult to assess IQ for indigenous versus non- indigenous populations?
Conceptual and methodological issues
- no control for
- health, education,
When does intellectual disability typically originate?
- Typically before 18 yrs
- Caused by any condition that impairs development of the brain before birth or in childhood years
What is a major concern regarding the use of IQ tests in Indigenous & Intellectually Disabled populations?
- classifying people
- Using a test that has biases
- not normed on those populations
- these classifications have real life implications
Which population is over-represented in the criminal justice system?
What does this tell you?
- Intellectually disabled (10%)
- when only 3% exist in total population!
What does this tell you
- people with low IQ may be led to please authorities with responses
- poor comprehension of causality (73% didn’t understand)
- easily led
- exaggerated willingness to talk
- of false convicted (22% were ID)
Why would someone fake an IQ test?
To gain advantage in some area.
- Access to social benefits
- Educational Financing
- Schooling and cognitive intervention
- Death penalty
- Military service
- Health Status
