You won't even think about trading under pressure if you are learning to trade the right way. You cannot trade under pressure if you read trading books, have mentors, be a part of peer group of traders. The people who are likely to trade under pressure are those who are greedy and want to make it a get rich schemes. Trading for them is short term and not a long term endeavor.
Even with trading the right way people still want to get that cool cash quick so they hasten up the process to achieve that and end up trading under pressure, so no one is exempted and that's because there are alot of money problems so they think trading can give them the money in no time forgetting that it requires patience. Another thing is seeing that it favours another and you want to go into it as well and end up handicapped under an pressure to do so and lose everything.