Intelligence lecture 4 Flashcards
Sex differences
What did scientists originally believe caused sex differences in intelligence?
Men were superior in mental abilities because women’s brains were smaller
What did Terman (1916) find about sex differences in intelligence using the Standford-Binet test?
Girls had slightly higher scores
What did Spearman argue about sex differences in intelligence?
There are no differences
How does gender relate to Fluid & Crystallised Intelligence as found by Cattell?
Studies show no difference between scores these for both genders
What did Court (1983) use to measure sex differences in intelligence and what did they find?
Raven’s matrices
Some small differences here and there but overall no difference concluded
What is a narrative analysis approach?
- Weighs up evidence across a number of studies
- Assesses whether each study supports the hypothesis or not
What did Lynn & Irwing (2004), Irwing & Lynn (2005) make to be better than a narrative analysis?
A meta analysis
What is a meta analysis? Why is this a good thing?
Uses results from numerous studies to calculate an average effect size
Means there’s a bigger sample so results are more meaningful
What are the Cohen’s d values for a small, medium and large effect size?
0.2
0.5
0.8
What did Lynn and Irwing find in their meta analysis comparing effect sizes for intelligence between males and females?
- <15 years, no difference (d = 0.02)
- 15-19 years: males scored 2 points higher (d = 0.16)
- Undergrads: males scoring 3-5 points higher (d = 0.22-0.33)
- Adults: men score 5 pts higher (d= 0.3)
What did Dykiert et al. (2008) and also Hunt & Madhyastha (2008) find that could explain sex differences in intelligence tests, rather than real differences?
Unrepresentative samples
What do Hyde (2005), Colom et al. (2000) and Spinath et al. (2008) all agree on?
They found no sex differences in intelligence - males and females are more similar than different
Which gender performs better on spatial abilities and which on verbal abilities according to Maccoby and Jacklin (1974)?
men = spatial
women = verbal
After further meta analysis research into spatial and verbal abilities of males and females, what is the general finding?
There are small to large effect sizes for spatial ability but only very small effect sizes for verbal ability (some larger in adolescence but small when combined - effectively doesn’t exist, especially in adulthood)
What did Benbow & Stanley (1983) find when looking into sex differences in 12-14 year olds taking the SATs early? In terms of verbal and maths scores
No differences in the verbal section
Boys did better in the maths section
- Twice as many boys than girls with maths scores higher than 500 (out of 800; 2:1)
- Four times as many boys with scores of at least 600 (4:1)
- Thirteen times as many boys with scores of at least 700 (13:1).
What did Blackburn (2004) find about the 13:1 ratio of high achievers in school?
It has reduced to around 3:1
What did Wai et al (2010) find about the closing of the 13:1 gap to around 3:1?
It has remained at 3:1/4:1 since the early 1990s
How much bigger are men’s brains than women’s on average?
10%
When can the brain size difference be seen?
adolescence onwards
Which brain regions did Allen et al (1991) and Steinsetz et al (1995) find that females have bigger?
- splenium
- corpus callosum
What does a bigger splenium/corpus callosum mean?
Tasks are more evenly distributed between the hemispheres
What is the difference between grey and white matter?
- grey processes information
- white transports information
What did Haier et al., (2005) find when using MRI to find areas of the brain relating to intelligence, in terms of grey and white matter?
IQ among females were related to more white matter areas and fewer grey matter areas than males
What ability has testosterone been related to?
Higher performance in spatial ability tasks
