It's dopamine (see also: caffeine) for me.
I don't recognize the approval mechanism myself.
For me it is that small hit when I think of/experience something new.
@avuko so your curiosity is rewarded
I understood caffeine was more a plant defence mechanism to kill off insects. A substance we have modeled in drinks to benefit us by prohibiting the feeling of tiredness. I need to look up the mechanisms...
These options are not all biochemical, and not all related to self-awareness or psychology. They are for sure not mutually exclusive. Which makes the poll flawed and fun
@Kristine Welcome to the wonderful world of methylxanthines!
I recently went pretty far down this rabbit hole (dopamine driven research into dopamine 
) wondering what the felt difference between tea and coffee was.
Caffeine is indeed a natural insecticide. Maybe caffeine messes with their nervous system as well?
What I found is that caffeine is the same substance in coffee and tea, but tea also has other methylxanthines (theobromine which is also in cacao, and theophylline) with different effects. Tea also has other chemicals which influence the caffeine uptake.
Anyway, have fun, there's much to explore there!
End of #InfoDump 
Kristine
⠠⠵ avuko