From a London Times article (praising the bravery of J.K. Rowling):
A friend believes people divide into sheep and goats. The sheep will never stray too far from their flock’s received wisdom because lone dissenters are picked off by wolves. Sheep are pleasant, biddable, placid, and panic when cornered. Sheep mainly aspire to a quiet life.
Goats are not nice: they’re cussed, belligerent, solitary. They scrabble and climb, cling to frozen rock faces. It’s not bravery that leads them far from low-hanging fruit and shelter into barren places with precipitous drops, or to ram their heads into hard objects and bigger foes. It’s their nature. They’re goats.
Some people put people into three classes. Sheep who go around with their heads down, not looking out for danger, wolves who prey on the sheep and sheep dogs who protect the sheep.