A University of Michigan study analyzed the brains of rats eating a favorite food. They found separate circuits for "wanting" and "liking", and were able to knock out either circuit without affecting the other (it was actually kind of cute - they measured the number of times the rats licked their lips as a proxy for "liking", though of course they had a highly technical rationale behind it).

One could come up with a story about how people are motivated to act selfishly but enjoy acting morally, which allows them to tell others a story about how virtuous they are while still pursuing their own selfish gain.

Rats! The neuroscientists were studying rats. It is troubling how easy it is to come up with these signalling stories to explain whatever observations we encounter.

What explanation can be suggested for a different mechanism for enjoying a food than the one for motivation to get food that doesn't rely on impressing our little rat friends with our culinary sophistication?