Popular Wharton professor Adam Grant, author of bestsellers Give and Take and Originals, once conducted a study involving hundreds of sales people that determined "cognitive ability" -- those super brainy skills required to carry out the most complex tasks -- was more than five times as powerful as emotional intelligence (EQ). 

In other words, Grant's study suggests that high IQ beats EQ with a knockout punch when it comes to skills related to job performance.

But what about when it comes to leadership effectiveness? Where does IQ stand with managing a team?

New research in the Journal of Applied Psychology finds startling evidence that too much intelligence can be harmful to your leadership effectiveness. 

Too Much Intelligence Not a Good Thing?

As reported by the British Psychological Society, the study involved 379 midlevel leaders (27 percent women, average age 38) at private companies in 30 mainly European countries, working in areas ranging from banking and telecommunications to hospitality and retail. The group was found to have an average IQ of 111 (above the general population average of 100).

It was found that leaders registering an IQ up to 120 had a positive relationship with leadership effectiveness. So far, so good.

Here's where it gets interesting: As IQ went up, the link between high intelligence and leadership effectiveness "flattened out and then reversed at an IQ of about 120."

From the report:

"Their scores in transformational and instrumental leadership were lower, on average, than less smart leaders; and beyond an IQ of 128, the association with less effective leadership was clear and statistically significant."

Although the new findings couldn't pinpoint exactly why very smart people seem to make poorer leaders, there is speculation that intellectuals put into leadership roles don't have the capacity to simplify tasks to the appropriate levels of simplicity for their people. They "are prone to complex language," the report states, and therefore are less inspiring.


It's no secret that highly intelligent people, overall, are usually associated with success. And intelligence does benefit leadership as we have seen. The issue here is whether it does so at every level of increasing intelligence.

If I may bring back the debate on IQ versus EQ that started this conversation, that's where I believe emotional intelligence will make up the difference. 

Daniel Goleman, who authored the internationally best-selling book Emotional Intelligence, argues that noncognitive skills can matter as much as high IQ for workplace success and leadership effectiveness.

In his emotional intelligence framework, once you get promoted, start leading others, and exercise your optimum people skills to influence, motivate, and inspire, that's when EQ beats IQ with a knockout punch.