Factors
Correlation
School grades and IQ
0.5
Total years of education and IQ
0.55
IQ and parental socioeconomic status
0.33
Job performance and IQ
0.54
Negative social outcomes and IQ
-0.2
IQs of identical twins
0.86
Take same test later
0.9
IQs of husband and wife
0.4
Research shows that intelligence plays an important role in many valued life outcomes. In addition to academic success, intelligence correlates with job performance (see below), socioeconomic advancement (e.g., level of education, occupation, and income), and "social pathology" (e.g., adult criminality, poverty, unemployment, dependence on welfare, children outside of marriage). Recent work has demonstrated links between intelligence and health, longevity, and functional literacy. Correlations between g and life outcomes are pervasive, though IQ and happiness do not correlate. IQ and g correlate highly with school performance and job performance, less so with occupational prestige, moderately with income, and only to a small degree with law-abidingness.
IQ
<75
75-90
90-110
110-125
>125
US population distribution
5
20
50
20
5
Married by age 30
72
81
81
72
67
Out of labor force more than 1 month out of year (men)
22
19
15
14
10
Unemployed more than 1 month out of year (men)
12
10
7
7
2
Divorced in 5 years
21
22
23
15
9
% of children w/ IQ <75 (mothers)
39
17
6
7
-
Lives in poverty
30
16
6
3
2
Ever incarcerated (men)
7
7
3
1
0
Chronic welfare recipient (mothers)
31
17
8
2
0
High school dropout
55
35
6
0.4
0