There are many more environmental factors than that, differences in behaviour between classmates, different friends, even the number of siblings are all environ

There are many more environmental factors than that, differences in behaviour between classmates, different friends, even the number of siblings are all environmental factors that I think make a difference. You can all go to the same school with the same teachers but if one of you have a teacher on a Monday morning and the other has the same teacher Friday afternoon after teaching a stressful ill-disciplined class, then the second child may have a different view of that subject forever.