Study finds 'toxic' employees hurt everyone at work

Toxic coworkers are not just unpleasant to work with — they pose a serious organizational risk. New research from Harvard Business School shows that employees who engage in bullying, misconduct, or other harmful behaviors can negatively influence their peers and impose significant financial costs on employers.

The study examined data from approximately 50,000 employees across 11 firms and found that so-called “toxic workers” — including those who harass coworkers, commit fraud, steal, or display extreme overconfidence — tend to spread their behavior to others. Colleagues exposed to toxic workers are more likely to disengage, leave the company, or even become toxic themselves.

One of the most striking findings is that avoiding a toxic hire can be more valuable than recruiting a top-performing employee. According to the analysis, a worker in the top 1 percent of productivity generates an estimated $5,303 in value, while avoiding a toxic employee can save firms roughly $12,489 by preventing turnover, morale damage, and potential legal exposure.

Despite these risks, toxic workers often remain employed longer than they should. Researchers note that managers frequently tolerate bad behavior because these individuals tend to be high performers on paper, creating a false tradeoff between productivity and workplace health.

The research underscores a critical insight for leaders: performance metrics alone are insufficient. Long-term organizational success depends on minimizing toxic behavior and protecting the broader social environment that enables employees to do their best work.