I would shake my head for 'no'.
Rover
:up: Me too. Some languages apply a yes/no response to the content of the question, and some apply a yes/no response to the truth value of the question. This makes for difficulties between a speaker of British English, and someone from, say, Japan. The polite (or at least uncontroversial) response to 'Don't you think?' is 'No'.
The case is further confused by some cultures who use a shake of the head to mean 'Yes' (Bulgarians, for example).
(Even between two English speakers, though, there is room for confusion. Last Christmas I asked my daughter 'Don't you want some tea?'. assuming she did. She answered 'Yes', and then looked at me like a madman when I brought her some.)
b