History of intelligence Flashcards
Francis Galton
- Cousin : charles darwin - book, became interested in heritibility of intelligence
- first to suggest people differ and measure intelligence: Eyesight, Reaction time
Alfred binet
- 1900s gov wanted a measure to identify children with learning difficulties
- binet simon scale, imp because allowed for comparison between children, intelligence seen as relative
Lewis Terman
- thought simon-binet scale was inappropriate cross culturally
-revised test = stanford binet test used on 1000 children
(helped to standardize levels of intelligence and create averages
William stern
one of major advances towards standardized testing
- developed IQ (Intelligence quotient)
- each person gets a number that indicates general intelligence
- mental age divided by actual age x100
Adults?
Robert Yerkes, Lewis Terman
2 intelligence tests, devised to test soldiers in order to assign roles to improve war effort.
Army alpha- Literate (8 subsets)
Army Beta - illiterate (7 subsets)
2 things happened as a result:
There was no improvement to the war benefit - maybe doesnt work?
Everyone became very interested in the idea of intelligence.
the controversy
- Heritibility of intelligence
Nature vs nurture
Galton studied obituaries - finding the more biologically close people were, they were more likely to have similar intelligence as measured by their stature in society.
IQ= stature in society.
- proposed the rational for twin and adoption studies. These studies gave us much information on the heritability of IQ
- Identical twins reared together 86% reared apart 76%
However the environment plays role biol variables family and school culture Bouchard and Loehlin (2001) created a framework that combines the genetic and environmental influences on behavior.
-Implications: Galton and eugenics
The controversy
Race differences in intelligence
(findings)
Herrnstein and Murray (1994) published a book called ‘The bell curve’
- analysis of IQ scores in the US
The cognitive elite.
- they suggested IQ was a better predictor of college attendance than social status or wealth.
- iq central factor of job performance.
= therefore people with higher IQs will be at the top of class structure.
They investigated many contextual factors that might effect IQ scores, and suggested that IQ causes poverty, or welfare dependence through corrilational analysis.
Found that black americans scored 15 points lower than white americans on the WAIS and therefore created a new bell curve.
Implications of Bell curve
-National IQ is getting lower.
Suggested that low socioeconomic / IQ mothers have more children than that of higher socioeconomic mothers, therefore by their logic smarter women are having less babies which reduces national IQ.
- Intervention won’t work.
Believed that IQ is inherited and fixed
Argued against extra training given to minorities.
Suggested that efforts have lead to decreased efficiency in the work force and increased racial tension therefore leading to ‘gifted’ people suffering
Spend more resource supporting high IQ people.
-inequallity is an inherited reality and that money towards positive discrimination should be used elsewhere.
Criticisms of bell curve
Book was initially well received but not by the scientific community who
highlighted issues with the corrilational analysis.
In 1996 a taskforce investigated the claims of the Book and suggested theres no real evidence to show that IQ differences between races are inherited, and that any such
differences are cultural.
The assumptions -
Gould (1995) ripped apart the 6 premises of the book in order to highlight the invalidity of author recemendations.
The stats
Kamin (1995) three criticisms in this regard;
Statistical knowhow. - correlation doesnt equal causation.
Validity of measures.
Research used to build arguments. - bias researchers
The dark side -
Many felt that the book was raising the issue of eugenics.
Critics, such as Gould, suggested that the book, without explicitly pointing to eugenics, inferred thoughts and practices that were consistent with it.
And the book isn’t helped by the fact that much of its evidence is based on that of Richard Lynn, who has been one of the most outspoken advocates of eugenics.
Gaulton suggested eugenics could be used to increase national intelligence- following this eugenics began informing policies in the US and in 1922 the model eugenic sterelization law stated low intelligence people should be subject to mandatory sterelization. This law was adopted by Hitler.
Sex differences
Terman (1916) found that girls scored slightly higher than boys when he originally tested the Stanford-Binet.
Court (1983) wrote the first systematic review on differences in intelligence across sex and found no differences.
However….
Richard Lynn wrote a letter to ‘The Psychologist’ magazine suggesting that his findings show this to be wrong.
Lynn and Irwing (2004) conducted a meta-analysis and found that men tended to score 3-5 points higher than women on Raven’s matrices.
Further research
Maccoby and Jacklin (1974) concluded that men score better on measures of spatial ability than women.
A series of meta-analyses revealed further differences in some specific abilities, and especially spatial abilities.
But why? Brain size. Evolution. Brain functioning. Testosterone. Stereotypes.
