Das New York Magazine erklärt:

* Also known as yupster (yuppie + hipster), yindie (yuppie + indie), and alterna-yuppie. Our preferred term, grup, is taken from an episode of Star Trek (keep reading) in which Captain Kirk et al. land on a planet of children who rule the world, with no adults in sight. The kids call Kirk and the crew "grups," which they eventually figure out is a contraction of "grown-ups." It turns out that all the grown-ups had died from a virus that greatly slows the aging process and kills anybody who grows up.