Practical Meaning of Human Cognitive Differences

1
Practical Meaning of Human Cognitive Differences

• Linda S. Gottfredson
• School of Education
• University of Delaware, USA
• June 28, 2009
• Cognitive Enhancement Symposium
• Future of Humanity Institute
• Oxford University

2
Point 1

• There are many cognitive abilities, but they all
  tend to rise or fall together, because they all
  share the same coreg

3
General intelligence (g)

• Individuals differences in g represent
  differences in
• Proficiency at learning, reasoning, thinking
  abstractly
• Ability to spot problems, solve problems
• Not knowledge, but their ability to accumulate
  and apply it

g
IQ
g
General
The domain-specific ability
fluid
The g core
V
Q
S
M
Others
Narrow
V verbal, Q quantitative, S visuospatial, M
memory
4
Point 2

• g level matters to some extent in virtually all
  life arenas, because all require continual
  learning and reasoning
• Examples

5
Important for planning, anticipating problems
6
Important for dealing with the unexpected
7
But practical value of g level differs by task
complexity life arena
correlation with IQ

• Standardized academic achievement .8
• Job performancecomplex jobs
• Years of education .6
• Occupational level
• Job performancemiddle-level jobs .4-.5
• Income .3-.4
• Delinquency -.25
• Job performancesimple jobs .2

• g

8
Typical life outcomes along the IQ continuum
Odds of socioeconomic success increase
9
Critical thresholds along the IQ continuum
X
X
X
50/50 chance of Mastering elementary
Doing well enough
in Doing well enough in college
school
curriculum
HS to enter 4-yr college to enter
grad/professional school
Most critical Ability to function
as threshold independent
adult
10
IQs not raised, so IQ thresholds must fall, when
higher of population attends college
X
X
X
X
X
50/50 chance of Mastering elementary
Doing well enough
in Doing well enough in college
school
curriculum
HS to enter 4-yr college to enter
grad/professional school
Most critical Ability to function
as threshold independent
adult
11
Point 3

• Human diversity in g is far greater than most
  people realize
• Examples

12
Military requires minimum trainabilityArmed
Forces Qualifying Test (a test of g)
Military enlistment thresholds
10th
15th
30th
X
Most military jobs require at least 30th
percentile
Military policy forbids induction below 15th
percentile
US law forbids induction below 10th percentile
13
Estimated levels of usual cognitive functioning
U.S. Dept of Education 1993 survey of adult
functional literacy (nationally representative
sample, ages 16, N26,091)
Routinely able to perform tasks only up to this
level of difficulty
14
Estimated levels of usual cognitive functioning
U.S. Dept of Education 1993 survey of adult
functional literacy (nationally representative
sample, ages 16, N26,091)
Difficulty based on process complexity

• level of inference

• abstractness of info

• distracting information

Not reading per se, but problem solving
15
Item at NALS Level 1

22 of US adults
78 of adults do better

• Literal match
• One item
• Little distracting info

80 probability of correctly answering items of
this difficulty level

16
Item at NALS Level 2
27 of US adults
51
22
X

• Simple inference
• Little distracting information

17
Another item at NALS Level 2
27 of US adults
51
22

• Match two pieces of info

18
Item at NALS Level 3
31 of US adults
20
49

• Cycle through complex table
• Irrelevant info

19
Item at NALS Level 4
17 of US adults
3
80
Or,
Solved

• More elements to match
• More inferences
• More distracting information

20
Item at NALS Level 5
3 of US adults
97

• Search through complex displays
• Multiple distractors
• Make high-level text-based inferences
• Use specialized knowledge

21
Estimated levels of usual cognitive functioning
U.S. Dept of Education 1993 survey of adult
functional literacy (nationally representative
sample, ages 16, N26,091)
US Dept of Education People at levels 1-2 are
below literacy level required to enjoy rights
fulfill responsibilities of citizenship
Could teach these individual items, but not all
such tasks in daily life
22
So, NALS 2 represents another critical threshold
NALS 1-2
Military enlistment thresholds
10th
15th
30th
X
23

Moreover, new technologies make life
increasingly complex, which puts yet higher
premium on g
24
Point 4

• The landscape of human cognitive diversity should
  inform debates over whose intelligence should be
  enhanced, how, and for what ends
• Examples

25
Nation-level implications of enhancement?
Current standard
Higher Higher less equal (Mean 100/SD
15) (Mean 105)
(Mean 105, SD 17) Innovators
5 9.2 11.5
Dependents 5 2.3 3.9 gt IQ 100
50 62.9 61.6 lt IQ 100
50 37.1 38.4
Potential debates about whom to target, and
whyequality? productivity?
Tail wind
Head wind

1.0
4.0
2.9
But suppose we raise the whole IQ bell curve by
some means

1.0
1.6
1.7
26
Nation-level implications Carrying capacity
Dependents
Innovators
Maintainers

Tail wind
Head wind
27
Nation-level implications Carrying capacity
Dependents
Innovators
Maintainers
Current standard
(Mean 100/SD 15)
Innovators 5 Dependents
5 gt IQ 100 50 lt IQ
100 50
Tail wind
Head wind

1.0

1.0
28
Nation-level implications 5-point rise
Dependents
Innovators
Maintainers
Current standard
Higher (Mean 100/SD 15)
(Mean 105) Innovators
5 9.2 Dependents
5 2.3 gt IQ 100
50 62.9 lt IQ 100
50 37.1
Tail wind
Head wind

1.0
4.0
Quadruples the ratio

1.0
1.7
Almost doubles the ratio
29
Nation-level implications with rise bigger SD
Dependents
Innovators
Maintainers
Current standard
Higher Higher less equal (Mean 100/SD
15) (Mean 105)
(Mean 105, SD 17) Innovators
5 9.2 11.5
Dependents 5 2.3 3.9 gt IQ 100
50 62.9 61.6 lt IQ 100
50 37.1 38.4
Tail wind
Head wind

1.0
4.0
2.9
Smaller but still huge effects

1.0
1.6
1.7
30
International implications

Estimated world average
Tail wind
Head wind
Countries ethnic groups currently differ greatly
So, many competing goals
31
References

• Gottfredson, L. S. (1997). Why g matters The
  complexity of everyday life. Intelligence, 24(1),
  79-132.
• Kirsch, I. S., Jungeblut, A., Jenkins, L.,
  Kolstad, A. (1993). Adult literacy in America A
  first look at the result of the National Adult
  Literacy Survey. Washington, DC US Department
  of Education, National Center for Education
  Research.

32
Thank you.

• gottfred_at_udel.edu
• http//www.udel.edu/educ/gottfredson