When can a kitten leave their litter safely?

What risk is there for the new owner that gets a taken from its mother and siblings too early?

They are often lacking social skills with other cats, they are more likely to be more vocal, and they are more likely to become aggressive if afraid of something or someone.    They won’t have the crucial social skills needed and thus often become involved in more fights, or get picked on.   They are clueless about social behaviour and body signals from other cats.    They also didn’t have the chance to learn from their mom and siblings about how to play without getting too rough and therefore are more likely to bite and scratch humans more.

They missed their chance to see it from their mother and siblings and didn’t get to practice it themselves when they were young.  The consequences of leaving their litter too early can last a lifetime.