Define your terms…
What is social conservatism?
What is a progressive society?
Without knowing more about how you view these systems, one might make the argument that the most progressive societies are those which respect social conservatism.
For instance… Is it progressive for a society to be liberal with release of new drugs on the market which haven’t been tested thoroughly? Drugs which might cause unforeseen complications in the distant future of those who rush to take them.
Or would it be progressive for a society to exhibit conservative patience and security for the well being of its citizens over the agenda of big pharm?