Individuals as groups, groups as individuals
People exist at different times. My life, for instance, consists of me-at-age-five, me-as-a-teenager, me-as-a-university-student, and of course many other temporal stages (or time-slices) as well. In a sense, then, we can see a single person, whose life extends over time, as akin to a group of people, each of whom exists for just a short stretch of time.