They ARE evolving. My kid was born with a taste for spicy food. When he was about one he used to try to swig the spicy mayo bottle. When he was two he was doing the “more” gesture for more Sriracha on his burrito meat. He’s three now and regularly eats off his Dad’s plate when he has food that makes my nose run and eyes tear up. He will probably be snorting Pepper X by his teens.