You are wrong as mine opinion. Monkeys will not give a fuck about masturbate to a porn or even by seeing other monkeys doing sex in front them. Your example is about an action, because it true that a monkey can become addicted to alcohol as like nicotine but because is a chimical external factor. While with porn you don’t give them nothing, humans get addicted to porns because our brain is evolved to reach the 4th dimension of logic, that’s mean thinking and feeling something you don’t see in front of you. When you have your dick on your hands and watching porn you get horny not because the big tittis of Alexis Texas but because your evolved brain thinks of that titties on your face while you call Alexis an horny slut. That’s the imagination that monkeys miss, and that’s why they cant be addicted at Alexis wonderful butthole.