Training vs toxic. Why training wins.
A 2016 study by HBS featured in Forbes Magazine found that a company stands to lose $12,489 (USD) to replace a toxic worker while employing a superstar (someone in the top 1% of performers) will add an extra $5,303 (USD) of performance. So even if you employ a fantastic performer who is toxic, you still lose.
How many times have you seen someone who is toxic transform into a genuine, trustworthy person? It can happen but not often. Major life events have a habit of kicking us in the teeth and changing our perspective, but transforming a toxic individual is the exception rather than the rule.
But take a well respected, trustworthy colleague and give them the right training and support and it is much easier to improve their performance. And it builds trust within the team, improves morale and encourages others to put in greater effort. So it's really a no brainer. Check out the emerging swans that you already have in your organisations before you hire a turkey.
Simon Sinek, the wonderful British American leadership speaker sums it up way more eloquently than I ever could in his trust vs performance video. I recommend taking a few minutes to watch the video here. It will be worth your time.