This time of year viruses carry health misery around offices, but according to the latest science, it's not just the flu that's catching. A wide range of behavior, from laughter through obesity, has been shown to spread through networks much like the latest bug.

And now, according to recent studies, we can add one more item to the list of the highly contagious: being a jerk.

You know that an obnoxious boss can make life miserable for his or her direct reports, but new research covered at length in HBR this month, shows that tormented victims are actually more likely to engage in office nastiness themselves, thereby spreading the unpleasantness in a widening circle around an organization.