What is the role of HR in culture change?

Recently I spoke to a large group of HR people, and the question came up again, "What is the role of HR in culture change?" This is the most common question I get asked by HR people.

My answer - and I don't remember ever thinking it this clearly before - is that HR can be the organisation's conscience. Holding the line on the values, when behaviour is showing up which is out of line with what everyone agreed to, when the line leader is struggling with a decision loaded with values-dilemmas, when decisions are being made which are very short term in nature. To be the one who takes that stand takes courage, and I do see this mantle most naturally sitting with the HR team.

The best HR people I have seen in operation have developed a role with their line leader where the leader turns to them to provide this voice, because sufficient trust has been built that they know that HR's view will be courageous and aligned with those values aspirations. The advice will not always be taken - that's not the point of asking for advice, right? - but it will be heard and respected.

There are many practical tasks HR can do to contribute to culture, but this is the one which I believe adds the most value. The challenge is to do it in a way that is strong, but not self-righteous.

Have you tried doing this? How did it work? Love to hear your views.