Hmm. I suspect there's a tiny little bias, possibly politically influenced, whereby signalling that you are nice implies signalling that you are irrational: naive, woolly-minded, immature, not aware of how the world really works, whatever.

But it is rational for us to oppose torture because public acceptance of torture is positively correlated with the risk of members of the public being tortured. And who wants that? It is also negatively correlated with careful, dispassionate, and effective investigation of terrorism and other crimes.

I also oppose it because I love my neighbour, an ethical heuristic I would also defend, but it's not to the point in this case.