Inductivist

The MIDUS Study asked respondents if their spouse had ever been unfaithful. I wanted to identify respondent characteristics that predict this.

Logistic regression coefficients

Men (sample size = 717)

Extraversion .12
Negative emotionality -.02
Conscientiousness -.15
Agreeableness .40*
Openness to experience .01
Age -.03*
Social class .00
Religiosity -.27*
BMI .00

*statistically significant

Of the Big 5 personality traits, only being agreeable predicts being cheated on for men. Older men are less likely to have this happen, as are religious men. Body mass index has no predictive power.

Women (sample size = 850)

Extraversion -.11
Negative emotionality .01
Conscientiousness -.44*
Agreeableness -.03
Openness to experience .43*
Age .00
Social class .00
Religiosity -.14*
BMI .01

*statistically significant

For women, conscientiousness lowers the risk of being cheated on, while being open raises one's chances. The only other predictor that matters is religion: religious women are less likely to get cheated on.
 
By the way, my experience with the data is the same as that of Rodney Stark as described in What Americans Really Believe. Compared to each of the Big Five traits, religiosity is a more potent variable. It frequently predicts outcome measures more strongly. Add this to the finding that the heritability of religiosity is .5, and perhaps Stark is right that religiosity should be considered a major personality trait.