There's no silver bullet. It's equally hard to determine when a manager is acting against subordinates because of petty grudges, or when a manager is acting against subordinates because they're bad at effectively telling subordinates what they want. I think that's kinda the job you sign up for when you choose to join higher-level management.
Caste-based discrimination would be a pretty serious charge against a manager, surely sufficient grounds for termination. We need to have a talk of how we are going to determine when it's happening if we are seriously considering policies to act against it.
