A study was recently conducted at North Dakota State University and Gettysburg College. Their study was measuring if people who like sweet treats (chocolate, pie, candy, etc.), have a 'sweeter' personality. Meaning if they have a sweeter disposition. They had people volunteer to rate their taste preferences on a scale of 1-10, after that they then took an agreeableness test(The Big 5!). After the results were in, researchers found a very strong correlation between liking sweets and being highly agreeable. They also had another voluntary survey, and people who liked sweets more, were more likely to be involved in the survey.
I believe there is a correlation between sweet foods and being sweet. The article seems to have pretty good evidence to back up their research. They also mentioned more causes and variables. Like maybe just the though of sweet food, like pie and chocolate, makes people act more agreeable, and be less angry. The article also suggested that sweet people have sweet babies. They think that if you have a sweet tooth you may have a sweet disposition. And psychologists believe disposition is a little bit heritable. So if I do my math right, "being sweet" should be heritable. I find significant evidence in this article that is very interesting and could probably be true.