Pygmalion Effect

For example, being told that you're good at something, can actually create a better performance.

But in the same vein, signalling to the user that they're bad at something, may have the reverse effect.

This is often called the Rosenthal effect.

Effort & motivation

• If you're told that you're the best football player on the team, and people are relying on you, you may be more motivated, and put in more effort.
• Likewise, if you're told that you have the ability to quickly learn to use a tool, you may be more motivated to then commit to learning how to use it.

Input quality

• If the user is told that they're bad at something, then it can knock their confidence, and influence future results.
• e.g., "you scored in the lowest 20% on Duolingo last month" could actually create a negative cycle, where your input quality was then worse as a result.