Does the language we speak shape how we think?

The blogosphere is all atwitter with the debate on the Economist website, the proposition being:

This house believes that the language we speaks shapes how we think.
http://www.economist.com/debate/overview/190

My friends in linguistics will not find any of this new, but I did made a small comment on the site, mostly because people were arguing that it was culture, not language that shaped thought, which I agree with (I'm sure the situation is far more complex than I care to think about), but didn't feel was actually relevant to the points being raised by the proposer.

I'm certainly not a hard-core Whorfian believer in linguistic determinism - that the language I speak somehow limits my experience of the world - but I do believe in linguistic relativism in its 'weaker form'. There's something about the grammatical structures and lexical items in our native language/s that we retrieve so habitually and 'naturally' that we don't even realise it until we start to learn another language as adults.

Nick Evans writes in his book Dying words: endangered languages and what they have to say, "Languages differ not so much in what you can say as in what you must say" (paraphrasing Roman Jakobson). In learning a new language, one often encounters distinctions that one wouldn't otherwise have to consider in their own language, like having to specify each time whether I'm going to get from point A to B on foot or by transport in Russian, or specifiying whether I farted on purpose or by accident in Sherpa (see here). Native speakers of these languages don't realise they're making these decisions because they're so automated, but for someone else trying to learn these languages, I don't think there's any doubt that they require a slightly different way of thinking about events in the world.

Anyway, whatever! Have a look at the live debate at the Economist site and see what others are saying!