The idea that introverts are more honest than extroverts comes from two assertions. First, studies find that “the more reflective [people] are, the more honest they become” (“Time Is Not Money” [The Economist, October 5, 2013 edition]), and second, introverts are more reflective than extroverts are (more [page 2]). So, it seems that all else being equal, introverts are more likely to be honest than extroverts are. The question though is, “when are all other things equal?”
As this article also reports, it matters what people are reflecting, time versus money for instance. We also know reflection could produce rationalizations justifying dishonesty such as when we pressure people to make decisions. So, just as cultures are important in determining how cooperative and innovative businesses are, dishonest cultures will influence introverts and extroverts alike.
Therefore, the point is that while we can assess personalities to determine who tends to be honest and dishonest (search “honesty assessments”), the best way to create an honest culture is through honest leadership using techniques encouraging honesty. This means paying attention to what we say when we seek to inspire and motivate our people. In other words, leading by example is only part of the formula. Active, relentless encouragement is there too.
So, yes, perhaps introverts tend to be more honest than extroverts are because of their reflective powers, but the reality is that the business culture tends to trump the reflective powers of both. That means an extrovert in an honest-encouraging culture will tend to be more honest than an introvert in a culture where honesty is politely bypassed in the name of profitable success.
Still, firms will continue to spend more time on trying to find the right people than on leading to create the right culture.