Split a group of people into three random groups.
Call one group the best, another group average, and the final group the worst.
Within a short period of time, these groups will become their labels.
This has implications for your community.
If you always give groups and people within your community the labels you want them to become, there is a good chance they will become those labels.
If you tell one group they contribute the best advice, another that they're the best at welcoming members, and another that they cause the least problems – they might become these labels.
This also works for individuals. Tell one member they are the most reliable source of newsd about that topic, another that they are great at weeding out spam posts, and they take more of these actions.