system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: Why do head/scalp massages feel so intensely good?

And why do they feel so much more euphoric compared to other kinds of massages?
gpt
IIRC: It triggers a dopamine response that has a calming de-stressing effect. Mothers gently touching an infants head while nursing, then later washing and brushing their child's hair calms them and makes them feel safe. Animals do this with grooming their babies as well. The licking and grooming is key to the young's ability to tolerate stress.