Understanding the relationship between education and general cognitive skills

Richard Cowan

2

Overview

Explaining the association

Past views

Early educational psychology

Development and individual differences

Dynamic relationship

Other factors

3

The associationThe correlation between school children’s educational achievement and general cognitive skills is typically about .5

One of the most reliable findings in psychology

Understanding it is important for

psychological practice, e.g. assessment of learning difficulties

curriculum planning

public debate

4

OriginsIdeas about the relations between education and general cognitive skills pre-date empirical psychology

Curriculum planning in education makes implicit assumptions about how education affects the development of general cognitive skills

There are subjects and ways of teaching that we believe encourage learners to think for themselves

At the same time differences between learners acknowledged, even if the contributions of prior knowledge, personality, motivation, and general cognitive skills disputed

Curriculum planning emphasis

5

Education General cognitive

skills

Individual differences emphasis

6

Education General cognitive

skills

Past views

From Plato onward, many educational theorists acknowledged effects in both directions

The assumption of mass educability led to downplaying the role of differential cognitive skills

7

19th century psychology

Faculty psychology originated in mental philosophy

Claimed mind consists of separate faculties

Number of faculties disputed

Cognitive faculties (memory, reasoning, morality, imagination) differentiated from emotions and will

Applied to education

Mental discipline: developing cognitive faculties so they could control the will and emotions

Subjects to develop particular faculties History for morality Mathematics, particularly geometry, for developing

reasoning Rote learning poetry to develop memory

Exercises and transfer Physical exercises that benefit

muscle groups produce gains that transfer automatically to activities that use them

The mental discipline view: activities that develop cognitive faculties would also automatically transfer

10

Herman Hesse

In The prodigy

Criticises conventional schooling for the neglect of personal development

And the mechanical approach of mental discipline

11

Pioneers of psychology

William James Edward Thorndike

Early educational psychology

James questioned faculty psychology

Thorndike assessed mental discipline claims empirically

Studies of learning did not find automatic transfer

Gains on tests of thinking skills were not related to choice of secondary school subjects as predicted by leading version of mental discipline

But individual differences in thinking skills did predict differences in school grades

Individual differencesThorndike found low correlations between scores on

contemporary cognitive skills – academic intelligence - tests

Combined with findings of limited transfer inspired his theory of numerous specific abilities

The only general ability is the ability to form associations

Differences in this ability depend on experience and genetic influences

SpearmanSuggested another explanation for low correlations between tests: one general ability, g, and many specific abilities

Developed factor analysis to show g

Identified two components of g:

Eductive – matrices tests have high loadings

Reproductive – vocabulary tests and factual knowledge

Misunderstanding g

In 1920s Spearman resisted identifying g with intelligence because of the confusions and controversies talk of intelligence involves and common misconceptions

These still exist

Belief that differences in intelligence test scores wholly due to genetic variation: refuted by behavioural genetics

Belief that intelligence is fixed: no foundation (Binet)

Variability in g is not all genetic

Heritability is the amount of variation between individuals that is attributable to variation in genes

It varies from 0 to 1 or from 0% to 100%

Comparisons of MZ (identical) twins and DZ twins have been used to estimate heritability

Although studies vary, in general estimated heritability of g increases with age: 20% in infancy, 40% in middle childhood, 50% in adolescence and adulthood

Nor are maths and reading variability

The Twins Early Development study is a longitudinal study of identical and non-identical twins in the UK

In samples of up to 5000 pairs of twins, heritability of 10-year-olds’ maths and reading is similar to that of g (36 - 48%)

That is notable but much less than 100%

But misunderstanding persists

‘Parents have long battled to persuade their children to master new spellings and learn their tables, but they may be wasting their time. A new study suggests that both maths and reading ability lies largely in the genes.’

19

Absolute g is not constant

Performance on all general cognitive skills tests improves substantially with age during elementary school

This is why psychometric tests of general cognitive skills use a child’s chronological age in calculating standard score

Matrix reasoning (RAVEN SPM)

6-year-old 10-year-old 15-year-old0

25

50

75

100

Receptive vocabulary (BPVS II)

6-year-old 10-year-old 15-year-old0

25

50

75

100

And neither is relative g

Individual differences at one age are not perfectly related to differences at other ages

For example g at 7 years correlates about .4 with g at 9 and 10

And g at 9 years correlates about .6 with g at 10

Dynamic relationship

24

Education General cognitive

skills

Assessing dynamic relationshipsRequires a longitudinal design, with repeated

measures of both education and general cognitive skills (g)

Influence of education on g: If education at time 1 predicts g at time 2, even when controlling for g at time 1

Influence of g on education: If g at time 1 predicts education at time 2, even when controlling for education at time 1

English, Maths, and g

The Twins Early Development study collected data on English, Maths, and g from children at the ages of 7, 9, and 10

Selecting one member of each twin pair who participated at all ages yielded a sample of 1074

I ran regressions of data at 9 on performance at 7, and regressed data at 10 onto performance at 9

From 7 to 9: βs and overall R2

9-year-old

7-year-old g English Maths

g .27* .14* .20*

English .13* .45* .20*

Maths .19* .18* .34*

R2 .23 .44 .37

From 9 to 10

10-year-old

9-year-old g English Maths

g .47* .16* .16*

English .16* .48* .23*

Maths .08* .17* .40*

R2 .35 .48 .45

29

English t2

G t1

Maths t1

English t1

Maths t2

G t2

So

Each measure explains variation in the other at a later point even when prior performance included

Results consistent with dynamic relation between education and general cognitive skills

But this may not be the whole story

Taking into account other factors

31

Education General cognitive

skillsOther

variables

Other factors• Genetic factors• Contextual factors at home and school: support,

setting, and beliefs• Self-beliefs: mindsets, motivation, and self-

concepts• Deliberate or incidental practice

Much to find out!

33

Thank you

Institute of EducationUniversity of London20 Bedford WayLondon WC1H 0AL

Tel +44 (0)20 7612 6000Fax +44 (0)20 7612 6126Web www.ioe.ac.uk