Something I have gradually noticed afflicts those of my acquaintance who have a competitive spirit, is that competitiveness fosters stupidity.
I don't like to show people up online, so it's hard to give examples! I'll try to describe what I mean.
Suppose (to give a fictional example), a woman were to say to her friend at church, "In thirty years of making cakes I've found that using fresh eggs and fresh baking powder gives you a better rise than using old ones." And suppose her friend has a competitive spirit and replies hotly, "Well, I've been making cakes for my family every week for nine years and mine are perfectly satisfactory, thank you!"
She does listen, but what she hears is a competition starting up. She hears the other woman saying, "My cakes are better than yours." So that's what she responds to.
Except, that isn't what the woman is saying. She wasn't starting a competition, she was sharing a life lesson — which the competitive woman didn't benefit from because she missed it. She was too busy staying at the front of the race. She missed the point and she missed the opportunity to learn. All she ended up with was the reassurance of "I'm as good as she is."
A competitive spirit divides our attention three ways — how I'm doing and how she's doing (who's winning), and the subject matter in hand. It's hard to learn something new when there's clamour in your head, and hard to notice and evaluate accurately when you're tense and anxious.
Humility has a quiet eye — it observes thoughtfully and maintains the interior spaciousness to take new information on board. Humility is its own form of minimalism, preserving an uncluttered mind.