Jensen

Question 1

Definition of intelligence?

Answer 1

• the aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment
• intelligence quotient (IQ)

Question 2

What is the measurement of IQ?

Answer 2

• performance on intelligence tests is compared to population distribution
• norm: mean of 100, sd of 15
• 68% of the population have IQ between 85-115
• 95% of population have IQ between 70-130
• 99.7% of population have IQ between 55-145

Question 3

What did Jensen (1968) find?

Answer 3

• low SES children with low IQ measures outperformed middle/upper SES european-american children on paired association task and serial learning task
• IQ and learning: IQ correlated with learning scores in mid/high SES but not low
• discrepancy: IQ tests often include items that assess cultural learning, children from low SS families are disadvantaged
• culture-free tests: particularly large differences between group correlations in Raven’s Progressive Matrices, peabody picture vocabulary test is on receptive vocabulary so may be bias in language, culture, and context

Question 4

What are genetics?

Answer 4

• races: populations with different distributions of genes
• genetic differences manifest in virtually all anatomical, physiological and biochemical comparisons to date
• geographical/social isolation increases genetic differences

Question 5

What is heritability?

Answer 5

• the proportion of variation in a trait in a population that can be attributed to genetic differences
• genetic and environmental influences should not be considered independent of each other
• can vary substantially from one environment to another
• is a population statistic and doesn’t apply to individuals
• level of heritability in 1 group doesn’t mean its level will be the same in other groups
• high heritability doesn’t mean a trait is immutable

Question 6

What did the review consist of and find?

Answer 6

• 123 page review of recent research and debate
• research question: understand the discrepancy between the IQ and achievement in low/high SES
• main argument: open up genetics as a potential avenue of research into IQ differences
• differences in general intelligence: african-american IQ distribution is 15 IQ points below distribution of european-americans. african-american variance in IQ is smaller than european-american variance. partial genetic influence on these differences had been strongly denounced but not contradicted/ discredited empirically

Question 7

What is the issue with biased commentaries?

Answer 7

• article published with 9 commentaries
• next edition of HER had 5 more rebuttals
• all offered limitations of the argument but overlooked data
• Jensenism (belief that african-american are mentally inferior)

Question 8

What is the scientific truth?

Answer 8

• Jensen strongly disagreed that science should be sued to search for truth only in certain circumstances
• claimed it’s why the discussion of the possibility of genetic determination of racial differences in test scores has stopped
• just if something is ‘socially inappropriate’ doesn’t make it immune to scientific scrutiny, it may make it more necessary

Question 9

What is the Flynn effect?

Flynn, 1987

Answer 9

• worldwide intelligence test scores rise by 3 points per decade
• even with different test types an din different world regions
• explanations: genetic changes of this magnitude are extremely unlikely at this pace, suggests cultural/environmental influence in test scores

Question 10

What are culture-free tests of intelligence?

Answer 10

• if Raven’s Progressive Matrices is ‘culture-free’ then concern over why some cultures/SES groups consistently outperform others
• Raven test scores have shown some of the largest gains over time (Flynn effect)
• original progressive matrices now only used for children
• adults tend to score perfectly
• undermines Jensen’s reasons for assuming genetic source of gap

Question 11

What is the stereotype threat?

Answer 11

• knowledge of traits associated with low scores tend to reduce the scores in people who have those traits
• reminding women about their gender before a maths test leads to lower maths performance
• reminding African-Americans about their ethnic background leads to lower performance on intelligence tests

Question 12

What is the most current understanding of genetics?

Answer 12

• now genetic influence on almost all behavioural traits is accepted
• genetic research is done on large scale: whole genome, millions of genetic markers, thousands of individuals
• gene action is very complicated
• IQ is complex and highly polygenic
• many potential loci but small effects and rarely replicate
• current understanding of genetics makes it difficult to conclude that high heritability of traits indicate mean differences in group performance

Question 13

What impact did it have on interventions?

Answer 13

• Jensen’s paper focused on SES, not just race

- interventions did boost short-term IQ but gains faded to non-significance within a couple years

Question 14

What impact did it have on intelligence testing?

Answer 14

• one result of the outrage is that Jensen’s hope of empirical testing of the factors which influence individual differences in IQ and intelligence test scores has been completely stymied
• IQ and cognitive ability are psychometrically robust often accurately predict those outcomes they’re designed to predict
• evidence of genetic influence is strong but nobody is willing to investigate into IQ differences between racial groups