Yet research finds weak and sometimes inconsistent relationships between sales performance and extraversion, with three meta-analyses finding the summed effects to amount to .07 - a non-significant finding. A new study by Adam Grant from the Wharton School, Pennsylvania, suggests that the sweet spot for sales performance might instead be balanced between extraversion and introversion.
Grant looked at week-on-week sales performance (revenue earned) for 340 outbound sales executives over three months. All completed a big-five personality inventory beforehand, comprising extraversion along with the other four primary personality dimensions; the inventory required them to rate their agreement with various items using a seven-point Likert scale. Regression analysis on the data revealed no linear relationship between extraversion and sales performance, instead finding a quadratic effect. Specifically, performance rose with extraversion until a peak at 4.5, well before the maximum of seven. From this point, performance actually decreased.
In hard numbers, the performers at the peak made on average $151 per hour, versus $127 for those whose extraversion was a standard deviation below, and a more meagre $115 for those a standard deviation above. Grant's analysis confirmed that the findings were not being driven by a confound from other personality factors, for instance a toxic combination of low agreeableness and high extraversion which might invite conflicts.
Why might those falling more towards the middle of the scale perform better? Grant dubs these 'ambiverts' and suggests that they are more likely to engage in give and take with clients, falling back to listening as introverts tend to, but then being willing to act and engage. Meanwhile, the strongly extraverted may fall into a range of traps - the dark underbelly of their strengths - by dominating others, projecting overconfidence, and sending obvious 'influence' signals that may lead to prospective customers raising their defences.
Grant concludes that organisations may want to look harder at the relationship between personality and sales performance to guide recruitment strategies, and that they may 'benefit from training highly extraverted salespeople to model some of the quiet, reserved tendencies of their more introverted peers'.
Grant, A. (2013). Rethinking the Extraverted Sales Ideal: The Ambivert Advantage Psychological Science DOI: 10.1177/0956797612463706
Barrick, M. R., Mount, M. K., & Judge, T. A. (2001). Personality and performance at the beginning of the new millennium: What do we know and where do we go next? International Journal of Selection and Assessment, 9, 9–30. DOI: 10.1111/1468-2389.00160