Long, but important, quote from Chapter 1 of Law, Legislation, and Liberty:

“As the conception of evolution will play a central role throughout our discussion, it is important to clear up some misunderstandings which in recent times have made students of society reluctant to employ it. The first is the erroneous belief that it is a conception which the social sciences have borrowed from biology. It was in fact the other way round, and if Charles Darwin was able successfully to apply to biology a concept which he had largely learned from the social sciences, this does not make it less important in the field in which it originated. It was in the discussion of such social formations as language and morals, law and money, that in the eighteenth century the twin conceptions of evolution and the spontaneous formation of an order were at last clearly formulated, and provided the intellectual tools which Darwin and his contemporaries were able to apply to biological evolution. Those eighteenth-century moral philosophers and the historical schools of law and language might well be described, as some of the theorists of language of the nineteenth century indeed described themselves, as Darwinians before Darwin.

A nineteenth-century social theorist who needed Darwin to teach him the idea of evolution was not worth his salt. Unfortunately some did, and produced views which under the name of ‘Social Darwinism’ have since been responsible for the distrust with which the concept of evolution has been regarded by social scientists.

There are, of course, important differences between the manner in which the process of selection operates in the cultural transmission that leads to the formation of social institutions, and the manner in which it operates in the selection of innate biological characteristics and their transmission by physiological inheritance. The error of ‘Social Darwinism’ was that it concentrated on the selection of individuals rather than on that of institutions and practices, and on the selection of innate rather than on culturally transmitted capacities of the individuals.”