I know lots of people that didn't grew up in a supportive environment and have a high IQ. I mean on the level of "my parents/father (it's mostly the father) never cared about me and now I have sevear depression and tried to kill myself" level. And partially they were pregnant at the age of 13/14

And I did grew up in a supportive environment and am stupid as fuck.

Maybe on average, but you've got my ass who was put in the gifted program from 2nd grade on, with a single mom who was working two jobs and thus wasn't around much, and who couldn't afford childcare so I had to spend most of my before and after school time with my physically violent and abusive grandmother. Not that being in said program did much good (between the bad home situation and my ADHD, I was constantly in trouble at school), I didn't even finish my bachelor's in the end, but there were a few of us "smart" kids with fucked up home lives in there too.