Yeah meta studies. Meh. I mean they're cute. "Let's look for
  patterns in the existing data". But to me, that's interesting
  statistical work, not science... not really. It's the kind of
  stuff people do for newspapers and sociology and for designing
  public policy and such. Oh well. When it comes to it, not a
  whole lot REALLY changes in Science. Most of the stuff we
  figured out 100+ years ago is still mostly true enough and the
  stuff that we argue about is minutia. "New studies" keep ppl
  busy, either confirming common sense (which is what Science
  usually does best - telling us what we already know) or finding
  some "shocking" thing that, when you prick beneath the surface,
  turns out to be a load of crap that gets media coverage because
  it's novel or, more likely, has a political taint to it. Sells
  newspapers, solves the publish-or-perish issue and helps
  increase funding for next year. Rehashing common sense in
  different ways seems to pump out papers. Pick any ol' proverb
  and do a study. Pick a confusius say or folk wisdom, grab a few
  people, ask a few questions, do it in a scientific format, and
  you'll get published. That part isn't so bad. It's when people
  go LOOK PPL - IT'S SCIENCE! and get excited 'cause it's
  science...y. sciency Yeah. Sciency.