I can’t tell you how many exceptionally bright people I’ve worked with, partnered with, hired and fired, who although they had remarkable native intelligence, couldn’t “play well with others”. I’m sure you’ve experienced it yourself – beyond a certain level of intelligence, there seems to be a negative correlation between smarts and the ability to work well and communicate with others. Similar to the “Don’t Hire Prima Donnas” rule, this rule is meant to encourage you to take a close look at people’s attitudes and “emotional intelligence”. In the end, you will be much better off focusing on this issue rather than “smarts”, assuming you can count on a certain level of intelligence in your candidates. Testing for the ability to play well with others is a bit more difficult before people are on board, but again, the best way to go about it is to put them in scenarios (particularly stressful ones) they are likely to encounter in your company/industry. All the better if you can introduce team issues into the pre-hiring scenarios as well. Don’t be overly impressed by IQ – in the end it is not nearly as important a factor as the ability (and desire) to handle and make the most of people issues..