Unfortunately for the authors, today's scientific paradigm requires at least the semblance of a statistical analysis. Finding a numeric measurement for an aspect of human consciousness, such as "toxicity" (or how much of a jerk you are), can be quite difficult. For the empirical portion of the paper, the authors choose to define a "toxic worker" as one who has been fired for "an egregious violation of company policy" such as "sexual harassment, workplace violence, falsifying documents, fraud, and general workplace misconduct". In their data, 1 in 20 employees was eventually deemed "toxic".
While I'm sure most people can identify a jerk at the office, they might also tell the authors, "You keep using that word [toxic]. I do not think it means what you think it means."