As a parent of a kid like this: start early with low stakes. You can increase your child's tolerance for pressure. I sometimes hear my kid saying sometimes afte

As a parent of a kid like this: start early with low stakes. You can increase your child's tolerance for pressure. I sometimes hear my kid saying sometimes after a deep breath, "There nothing to it, but to do it". And then work on focusing on what they did better versus how they did in absolute terms. I see collapsing under pressure to be either a kind of anxiety or a fixation on perfect outcomes. Teaching a tolerance for some kinds of failure is the fix for both.