Face space also explains why the favorite trick of editorial cartoonists works so well. By exaggerating features on a politician's face — Bush's eyebrows, Obama's ears — cartoonists push it farther away from the center of face space, to places where it has less competition from other faces we have stored in our memory. As a result, we recognize people from hand-drawn caricatures as quickly as from photographs — and sometimes even more quickly.
That is Carl Zimmer, from the January/February 2011 issue of Discover, not yet on-line. Here is a short piece on how to draw caricatures.