Originally posted June 2018
Here is an excerpt:
As opposed to fear, distrust and anxiety, circuits of neurons in brain regions called the mesolimbic system are critical mediators of our sense of “reward.” These neurons control the release of the transmitter dopamine, which is associated with an enhanced sense of pleasure. The addictive nature of some drugs, as well as pathological gaming and gambling, are correlated with increased dopamine in mesolimbic circuits.
In addition to dopamine itself, neurochemicals such as oxytocin can significantly alter the sense of reward and pleasure, especially in relationship to social interactions, by modulating these mesolimbic circuits.
Methodological variations indicate further study is needed to fully understand the roles of these signaling pathways in people. That caveat acknowledged, there is much we can learn from the complex social interactions of other mammals.
The neural circuits that govern social behavior and reward arose early in vertebrate evolution and are present in birds, reptiles, bony fishes and amphibians, as well as mammals. So while there is not a lot of information on reward pathway activity in people during in-group versus out-group social situations, there are some tantalizing results from studies on other mammals.
The article is here.