A legitimate experiment to try: write down the names of the ppl
  who fit the profile of the MRA. Notice if the same names come up
  in conversations. Add any new names you find. The actual pool
  size might be very tiny but with noisy voices. It proves over
  representation of a tiny group. Once there is a group
  established (a stereotype filled with identities rather than
  impressions) - it can be further dismantled by seeing the
  members as individuals.