The brain might be the control center for the rest of the body, but the heart determines many things just as you pointed out. I once read a book about someone that had a heart transplant and suddenly became an alcoholic. In his quest to find a solution to the problem, he was able to get the medical history of his donor and guess what? The donor was an alcoholic as well.
The brain cannot differentiate between wants and needs, the heart does. Found your post via @dreemport