Tbh, I don't know much about it either. I read it on this subreddit. My take on it is that due to nervousness/social anxiety the oxygen flowing to our brain is restricted, causing me to stammer. I'm bilingual, and ironically I stammer more in Hindi(my native tongue) than English. I speak English much more naturally and fluently. It's like a Paradox. Maybe, it's due to the fact that I'm pretty confident about my English? Can be he the case. Recently I have also noticed that I avoid making eye contact and get nervous(never noticed it while debating on stage infront of a 1000 students🤦🏻). Do you have any tips for social anxiety?