Mail surveys among college students: do initial responders score differently from nonresponders on the 16PF?

A single experiment is reported which investigated possible personality differences between college students who responded to a mail survey and those who did not. 208 college students completed the 16PF as part of a class assignment. Then each student was mailed a survey dealing with either a national or local issue (environmental, media, or sports). Multivariate analysis of the 16 subscales of the 16PF yielded a significant interaction between sex and response type. Subsequent protected univariate analyses identified significant sex x response type interactions on scales Q2 (Self-reliance), F (Liveliness), and O (Apprehension). Mean differences on the Self-reliance and Apprehension were sex differences rather than personality differences between responders and nonresponders. The only mean difference for response type was on Liveliness and applied only to men; responders scored lower than nonresponders. Multivariate analysis of the global scales of the 16PF yielded a significant interaction between sex and response type. Protected univariate analyses indicated a significant interaction between sex and response type on the Extraversion scale and a sex difference; female nonresponders scored higher than male nonresponders. No other comparisons were significant.