Flynn Effect - Individual Differences A2

flynn effect

each successive revision of IQ tests leads to a re-norming if the new test against the population norms of the old.

Found in almost all societies and cultures, and has been present from the start of IQ testing.

James Flynn

Noted that each revised test had to be made harder in order to preserve a population mean of roughly 100.

compared these adjustments over time for 73 studies conducted on a total of 7,500 US children between 1932 and 1978

Increased length of schooling

IQ increases for each year of schooling to a ceiling effect, even in on-verbal tests (Cohen + Cohen, 1989)

can’t explain the larger flynn effect in non-verbal tests: the greater Flynn Effect in Gf rather than Gc.

Increased availability of schooling

Flyyns own preffered hypothesis is that better availability of educational opportunity means that people with high genetic potential are better able to realise that potential.

Predict a ceiling effect?

There is evidence that they Flynn Effect is levelling off (Teeside and Owen, 2000)

Type of schooling

less emphasis on rote learning, more on conceptual (and visual) understanding.

this type of learning might specifically train students for tests like Ravens Matrices.

Better nutrition

improvments in nutrition (removal of malnutrition) does indeed lead to higher IQ

might predict a ceiling effect

beneficial effects of nutrition seem to work to a ‘threshold’ model of avoiding deficiancy rather than ‘more is better’

this would predict IQ gains more through a ‘leveling up’ of lower scores than a raising of high scores

(Colom et al, 2005) claimed to find this in a Spanish Cohort.

test-taking sophistication

‘exam technique’; after IQs stop being culturally unfamiliar and you start to get a concept of how well to do on them.

plausible for early increases but “it becomes merely incredible when applied to the data as a whole” - Mackintosh, 2012:219

the cognitive simulation hypothesis

visual and technical equipment - all your tech turns out to be good for you

main competing theories

cognitive simulation hypothesis and nutritional hypothesis

Neisser, 1998; Greenfield, 1988; Williams, 1999; Schooler, 1998

still a mystery

Flynn Effect is starting to be seen in the developing world

multiple factors at work (family size, urban/rural effects)

rises in Gf much greater then Gc (consistent with test sophistication and cognitive simulation hypothesis?)