Extraversion and marital status: Here are the mean introversion scores for each marital status for Americans ages 30-49 (GSS data):
Mean introversion scores (N = 2,870)
Never married 13.0*
* p < .05, two-tail test, compared with married people
All groups except for widowed are significantly more extraverted than married people. Makes sense. Marriage is for homebodies. Introversion might help explain the lower divorce rate of Asians. Here are effect sizes:
Never married .46
The differences between married/widowed people and the other categories are small to moderate.