People--male and female--are exposed to testosterone as they grow: in the womb, at adolescence, and in adulthood. Most scientists believe that testosterone levels play a role in brain development. By the time we are adult, all of us have a basal level of testosterone that remains fairly stable throughout our lives. So testosterone levels aren't purely a guy's issue. But are high levels of testosterone good or bad for business?

Because it is associated with aggressiveness, it's often assumed that testosterone is great, at least for certain kinds of jobs. Day traders, lawyers, merger and acquisition specialists, to name a few. Though some have argued that less testosterone in our banks might have made them less risky, others believe that a zest for full-throttle competition is what makes certain people great at what they do.

What does testosterone mean for your team?

The reality is both more subtle and more worrying. Testosterone is implicated in poor judgment and weaker emotional intelligence. In one experiment, T (as it's called in the academic literature) was administered to women who were then asked to take a test routinely used to measure empathy. As the research team expected, the women's talent for picking up nonverbal signals was significantly impaired.

But even more interesting was the relationship between T and collaboration. Groups given testosterone orally proved less able to work together than groups given a placebo. Primarily, this was because those who had ingested the hormone demonstrated an "egocentricity bias"--meaning they were more likely to overvalue their own opinion and less likely to take seriously the views of their colleagues. Raised T levels, in other words, made everyone more self-centered and less able to tune in to others.

It's important to note that, because both men and women have varying levels of T, this research isn't about men. It's about individual, unconscious orientation. I hope we won't live to see the day when we all have to take hormone tests prior to interviews.

But we should pay attention, in interviews and assessments, to how clued in people are to one another. Because testosterone levels vary little within an individual, what you see today is probably what you will see tomorrow. As we increasingly need individuals with highly developed collaborative skills, we should perhaps be modest in our expectations of change.