Bias is inevitable. Unaltered distribution is permitted. Last modified May 31, 1996. Hackers aren't, contrary to media reporting, the people who break into computers. Those are crackers.
Hackers are people who enjoy playing with computers.
A hacker can be dramatically more effective than a non-hacker at a job, or dramatically less effective. Repetitive, simple jobs are a waste of a good hacker, and will make your hacker bored and frustrated. No one works well bored and frustrated. This is not consistent, and you shouldn't expect to see it all the time, but it will happen. This is most visible on particularly difficult tasks.