If this is how they defined toxic, then the findings of the study are simply tautological.
> avoiding a toxic worker (or converting him to an average worker) enhances performance to a much greater extent than replacing an average worker with a superstar worker
>avoiding a (worker that engages in behavior that is harmful to an organization, including either its property or people) (or converting him to an average worker) enhances performance to a much greater extent than replacing an average worker with a superstar worker
Well yeah, of course it does. A harmful worker causes harm. Duh.
It is better to remove a bad employee, than hire a better one. More urgent anyway.
citation needed