Race, social class, and negative emotionality

A stress reaction score was calculated for white MIDUS Study participants based on the following items: is tense and nervous; is sensitive, feels vulnerable; is prone to worry and feel anxious; is irritable and easily upset; has changing moods; can feel miserable without reason; is troubled by feelings of guilt and unworthiness.

I calculated the means by sex and social class (Sample size = 3,988):

Mean stress reaction score

Men
Low 6.61*
Middle 6.18
High 5.98

Women
Low 6.49
Middle 6.09
High 6.06

*significantly higher than high-status men

Low-status men are significantly more neurotic than high-status men. The gap between the two groups is three-tenths of a standard deviation (sd)--a moderate difference. The mean for low-status men is so high, it surpasses that of all female groups. There is a smaller gap between low-status and high-status women which doesn't quite reach statistical significance.

Now let's turn to stress reaction differences by race and sex:

Men
White 6.22
Black 6.03
Amerindian 6.04
Asian 6.57

Women 
White 6.14
Black 6.73*
Amerindian 6.59
Asian 7.12

* significantly higher than white women

Of the men, the Asian score stands out (although it is not significantly higher than white men--the Asian sample is only seven guys).  All minority female groups are higher than white women, although blacks are the only group to differ significantly. The black-white female gap is one-quarter of an sd--a small difference.  

This analysis of Add Health data also indicated higher negative emotionality among non-whites. (It also showed a gender gap for whites as well as for non-whites).

According to this study, heritability for negative emotionality is 48 percent, but I can easily see a nurturist explaining the gender/class/race pattern I just reported entirely in terms of oppression. It makes one an emotional wreck.

IQ and negative emotionality: The GSS asked respondents four questions: How many days out of the past week were you: 1) angry, 2) anxious and tense, 3) sad, and 4) fearful that something would happen to you? Answers were all intercorrelated. I converted them to z scores and summed them to create an index of negative emotionality (also called neuroticism). The alpha coefficient is .68.

Here are the mean scores for smart people (those scoring 9 or 10 on the vocabulary quiz) and for everyone else:


Mean negative emotionality (N = 935)

Smart group .62
Everyone else -.11


The difference between the two groups is significant at the 95% confidence level. The gap is 26% of one standard deviation which indicates a small difference.

The results seem right, but I am not sure why smart people are more neurotic. Perhaps a reader steeped in the science has an idea.

It does seem like there is a calmness that comes with not thinking about things much.