Does anyone else find it interesting that we use the same words to describe the taste of simple sugars and a set of behaviors designed to facilitate group living?
“Sweet”, as a flavor, is generally regarded as a pleasant flavor. It does not, however, mix well with every other flavor; while sweet can go with sour, it does not generally mix well with bitter or umami. (Except when it does, and then it’s awesome). Furthermore, it is regarded in higher esteem by children, with adults still enjoying the flavor but often preferring more bitter tastes (like coffee or wine) or umami flavors (like steak or eggs) on a regular basis. To “have a sweet tooth” (or, enjoying sweet flavors frequently even as an adult) is seen as a childish trait: see, for example, Hani-senpai in Ouran High School Host Club or, really, most of the characters listed here (WARNING: TVTROPES). The phenomenon is also discussed here (See? The tvtropes even caught me).
“Sweet”, as a personality, involves altruism, politeness, etiquette, and a soft voice. It is usually associated with females, and is seen as a desirable trait for them to have as well as being the default state for a “good” girl. This has led to a number of pet names for females: sweetie, sweetheart, sugar lump, sweetness, honey, honeycakes, and the derogatory “sugar tits” (and who came up with THAT particular turn of phrase exactly?).
Women are associated with children traditionally: “women and children first”, the idea of a stay-at-home-mom, a lot of the justifications for not allowing women the vote. Sugar is associated with both, as well as generally being pleasing to most humans. I bet there’s more to this story, but I’ve gotta go fight with IBM about my broken software so I’ll leave you to ponder.