The badges page says that the peer presure badge is awerded by deleted a own question with a score of -3 or less. I just deleted two questions with -3 but didn't got the peer-pressure badge.
I searched for badges peer pressure and got zero results.
I found this other question but it's about badge page layout but it only has a comment:
Should I wait for a while, is there something broken or the badge page is obsolete?