Programmers are like tornadoes. Think of them as forces of nature. They will do what they do. ... Design your practices accordingly.

Kaner, C., Bach, J., and Pettichord, B., (2002). Lessons Learned in Software Testing. New York: John Wiley & Sons. Lesson 181 (p. 168)  10:24:32 PM    

We find it misleading to consider bug counts per tester without carefully reading the individual reports. For example, some testers investigate more thoroughly than others, spend more time tackling harder-to-reproduce problems or harder areas to test. Their bug countes are often much lower than the group average. We usually call these people "senior testers" not "less productive."

Kaner, C., Falk, J., and Nguyen, H.Q., (1999). Testing Computer Software, Second Edition. New York: John Wiley & Sons. p. 101  9:52:38 PM