I hate this argument, it’s used in a lot of mental health issues. Just because people have the same condition doesn’t mean they will present the same especially for conditions affecting the brain.

FAS very much can make someone more violent and aggressive just due to the parts of the brain it affects (pré-frontal cortex).

FÃS didnt make him slit the guys throat but it very much did contribute to it.

Not everyone with schizophrenia is violent (the vast, vast majority are not) but it can make someone who was previously non violent into being violent.