Except that's exactly what is up for discussion, and so far there is no evidence that this is the case. There's a big difference between muscle memory, neuroplasticity, and playing the piano than their is for sitting on the couch and consuming violent media.
> Pretending they don't exist doesn't make them magically disappear.
Saying they exist doesn't make them magically appear.
> Furthermore, human behavior is often learned for the collective
Yes, that's also how morals work. The more people are exposed to something, the more morally acceptable it becomes.
> Now please explain - not being snatky - how that's nonsensical.
Short witticisms like "you are what you eat" or "you are what you learn" are shallow and vastly underestimate the subjects at hand in exchange for a quick nod. Such as "we are greater than the sum of our parts".