I enjoyed this article on law.com, At Firms With 'No Jerks' Rules, Abusive Attorneys Need Not Apply. For obvious reasons, I'm a big fan of this philosophy, as I personally would not hire a jerk and certainly don't like working with or for them. But it goes beyond mere preference - research has shown that abusive employees and workplace bullying can be found in a lot of companies. And while the actual cost to employers of such behavior is difficult to measure, there is no doubt that employees who witness this feel less job satisfaction and loyalty. Based on my experience, those two factors are probably some of the best determinants of an employee's quality of work.
The article mentions a Seattle firm that attempts to avoid future problems by using their HR department to meet with staff who cause or are victims of negative incidents. This firm has also been named one of the Top 100 Best Places to Work for five years running. Coincidence? I doubt it.
We are living in an age where loyalty does not seem to mean much, and many people will change jobs every 2-3 years. Unfortunately that lack of loyalty does cost companies money in the long run, in training new employees, lower profits, and even employment litigation. One way to improve loyalty is to screen interviewees based on personality, and to put in place policies that allow problem employees to be dealt with in a way that will encourage harmony in the office. Call it enhancing your corporate culture, finding candidates that "fit", or whatever. Nobody likes to work with jerks.