Actually there are more. Which ones are you talking about? Which encounters do they exist within and which encounters do they not exist within? I would like to know the categorical difference you are implying. I have focused on oxytocin because the scientific zexual finger is pointed directly at it. It's in luzt encounters, orgazm encounters, breastfeeding encounters, massage, skin hunger experienced by children and encounters, etc. It seems to touch on all of them. As far as my personal research goes I haven't seen that chemicals creating a categorical difference that it seems you are implying, but when considering fMRI categorical discoveries began to become more obvious. But, what about those chemicals? What am I missing that you have noticed?