Teaching Manners?

A recent altercation with a very rude person has led me to muse on the place of manners in education. As with so many elements in a young person's social development, the line between the parent's role and that of the teacher is very blurry when it comes to issues such as manners. Of course we can reinforce good interpersonal skills through modelling the 'right' or 'nice' way to interact; but I wonder whether, as with so many other skills, social skills need to be explicitly taught?

Take metacognition, for example. Throughout my teacher education course I've been struck by how often we are encouraged to teach students to think about thinking, to analyse their own learning, be able to characterise it in order to see how best they can help themselves learn. More and more often, skills like this are being highlighted, explicitly identified as something we need to teach students; the implication is that we cannot expect them to think about thinking on their own.

Is there a similar need for expliit discussion of social skills?