Are the personalities of software testers different from others working in software development? To answer this question, a survey was conducted that asked respondents to complete the 50-item International Personality Item Pool (IPIP) test. Volunteers were sought from online groups, an industry conference, and an industry conference email list. Of 182 respondents, 82 (45 percent) were software testers, 57 were programmers, 28 were managers, and 15 were a mix of analysts, consultants, architects, and product designers. Respondents were drawn from a broad range of nationalities, and a majority of the respondents were male.

The data was not normally distributed, so Mann-Whitney U tests were applied to test for differences between software testers and nontesters across five dimensions (traits) of personality. Testers were found to score significantly higher for the dimension of conscientiousness (p = 0.011). The result was interpreted as showing that 66 percent of nontesters were below the average conscientiousness of a software tester. A post hoc power analysis found that statistical power was relatively low for the testing of the other four dimensions, making it difficult to draw any conclusions about them.

Unfortunately, the statistical analysis does not account for multiple comparisons. A simple conservative adjustment to recognize that five statistical tests were performed would mean that the difference found for the dimension of conscientiousness would narrowly miss statistical significance. Combining several categories of professionals into the group of nontesters also seems questionable. This paper, therefore, is recommended only to those researching the influence of personality in software development.