New research out of the University of Copenhagen finally puts to rest the age-old argument around what’s better: being an extrovert or being an introvert? I have friends who are on both sides and super successful in their careers, but it’s still one of those things where if you are one or the other, you usually believe what you are is the best.

Well, in terms of lifelong earnings the data is pretty clear you want to be an extrovert! From the study:

One striking result is how much the trait of conscientiousness matters. Men who measure as one standard deviation higher on conscientiousness earn on average an extra $567,000 over their lifetimes, or 16.7 percent of average lifetime earnings. Measuring as extroverted, again by one standard deviation higher than average, is worth almost as much, $490,100. These returns tend to rise the most for the most highly educated of the men.

For women, the magnitude of these effects is smaller (for one thing, women earned less because of restricted opportunities). Furthermore, extroversion is more strongly correlated with higher earnings than is conscientiousness, unlike for the men.

Yeah, that’s a half of million dollars! That’s life changing money for most people!

Here is something else that came out of the study that I thought was fascinating, people who are ‘agreeable’ by nature, actually make less money!

It may surprise you to learn that more “agreeable” men earn significantly less. Being one standard deviation higher on agreeableness reduces lifetime earnings by about 8 percent, or $267,600. In this context, you can think of agreeableness as meaning a person is less antagonistic and more likely to consider the interests of others. You might have thought agreeableness would be correlated with higher earnings but alas not.

So, here we are as HR pros telling all of our employees who want to be leaders they should be more ‘agreeable’, put the interests of others above your own, etc. What we are really telling them is “hey, here’s how to ensure you’ll make less money in your career!”

I think we see this in our world today. We tend to want to believe we all want ‘servant leaders’ when it comes to someone leading us individually, or leading our companies. But, for the most part, most of our great leaders we can point to, male and female, are still overwhelmingly extroverted and mostly directive in their style of leadership.

One last thing that came out of the study is that being smart and being extroverted is not correlated. Why does this matter? Well, being smart does correlate to higher income as well. So, when we go try and select great employees we tend to just look at intelligence. Which is necessarily bad. If you are going to try to increase your talent, starting with smart people is never a bad idea, but in the long run, it’s more than just IQ:

Another interesting result from the data is that IQ and conscientiousness are not very well correlated. That implies that finding ideal workers isn’t so easy. The quality of openness, however, is moderately positively correlated with IQ, so you might expect that the smarter workers are more willing to experiment and try new things.

So, do you have to be extroverted to make more money? No, but it’s easier and more likely if you are. If you’re introverted, by nature, it wouldn’t hurt to work on your outwardly extroverted self. We all have the ability to be extroverted and introverted in certain situations. The key for earning more income is being extroverted in a professional setting.

Okay, my introverted friends! Tell me why this research is complete B.S.!