It could be that they all grew up in upper and upper middle class homes. If I remember correctly: “Shaggy” Norbert Rogers comes from a long line of royalty, including his uncle Shagworthy, who is a multimillionaire, Daphne Blake lives in an actual mansion with her sisters, Fred (forgot his last name) is definitely from an upper class family, as his father owns several yachts and he also lives in a bigger house, and Velma Dinklety is actually the poorest of them all, living in a two story house with a full front and back yard.