Lecture 5 Flashcards
what are issues with intelligence tests?
- validity
- reliability
define validity
whether the test measures what it claims to measure
what are the three types of validity and describe
FACE VALIDITY- if it looks like it is going to measure what it is supposed to
CONCURRENT VALIDITY- if it has a positive relationship with other measures of intelligence.
PREDICTIVE VALIDITY- predict ‘real world’ measurements intelligence or achievements
how valid depends on what the definition of intelligence is.
what are the two aspects of reliability?
INTERNAL- has a number of items that correlate positively with one another- this suggests they are measures of the same construct.
TEST-RETEST- stable over time- expect IQ scores to be similar across test sessions.
how much has it been suggested IQ scores fluctuate between two testing sessions and who developed this?
15 points (benson 2003)
what did Jones and Bayley 1949 find?
IQ scores of adolescents at 18 years were positively correlated with their IQ scores at 12 years (r = .89) and 6 years (r = .77).
talk about long term stability in IQ tests
in general the older the age in a earlier IQ test the more correlation the score has with IQ score at age 40.
what is the Flynn effect?
The scores on intelligence tests have a tendency to fluctuate.
The scores of intelligence tests change continuously from year to year.
Flynn (1981) discovered an year-on-year rise of intelligence test scores (whenever a new/revised IQ test was compared to an older/previous IQ test).
In particular, Flynn found that if a group of participants averaged an IQ of 100 on the original WISC (1947/1948), they averaged 108 on the WISC-R (1972).
→ in a period of 24 years participants had gained 8 IQ points
Flynn (1984) looked at 73 studies (covering 7,500 US white participants aged between 2 and 48 years).
highest rise in IQ occurred in the non-verbal tests (fluid intelligence; 5.9 IQ points per decade) and lowest gains were in verbal tests (crystallised intelligence; 3.7 IQ points per decade)
→ due to better schooling? (However, IQ gains in verbal vs. non-verbal IQ should be reversed)
give possible explainations of the Flynn effect
Generations are getting more and more intelligent
→ unlikely, we would expect to find more geniuses in the world
→ these gains are far too to rapid to result from genetic changes
Length of schooling → important, but mainly relevant for verbal tests
Test-taking sophistication (people become more familiar with IQ tests)
→ does not explain the difference between verbal and non-verbal IQ tests
Child-rearing practices (parents are more interested in their children‘s intellectual development)
→ some evidence, but educational programs have probably no lasting effects on IQ
! Cognitive stimulation hypothesis (visual and technical environment, TV learning)
→ little direct evidence
! Nutrition (e.g. nutrition has been linked to brain size)
How Can we intentionally improve intelligence with education?
Increase amount of formal education
Correlation with IQ quite high (r=0.55 to 0.90)
Children’s IQ declines during the summer (Holiday effect)
→ Causality unclear and ethically difficult to investigate
How Can we intentionally improve intelligence with nutrition?
Nutrition → Slow food instead of fast food
How Can we intentionally improve intelligence with cognitive enhancers?
Cognitive enhancers “Smart Pills”
Ritalin (methyphenidate) can enhance attention, (working) memory, etc.
Ampakines (boost glutamate)
Modafinil (DA reuptake inhibitor) enhances memory and planning
→ Findings are inconsistent (35% of the studies reveal no effects)
→ For executive function, brain imaging studies show reduced activation (indicative of higher neural efficiency) but no effect on cognition
→ Individual variability: ability level, personality and genotype
→ Effects are small and probably of little use for the real world
