For instance, he has been discussing the connection between female sexual history and later success in marriage. It turns out that the later a young woman becomes sexually active and the fewer sexual partners she has before marriage the better her chances of marital stability (see here, here and here).
There are several interesting graphs showing the statistics, including the one below.
What's notable is how steadily the first five bars rise. For each two year period that a girl delays sexual activity, there is a significant improvement in her chances of marrying successfully, with the effect lasting up to the age of nineteen.
There's a message to parents here not to give in to the advice that "she's going to start some time anyway." It does make a difference if the girl holds off when she is in her mid-teens.
The Social Pathologist has also written an interesting and very accessible post on empiricism. To briefly summarise: it was traditionally held that the mind was able to grasp elements of both empirical and non-empirical reality (empirical being defined as directly accessible to the senses).
However, the scientific revolution demanded that knowledge be tested through sense experience. This yielded success in the physical sciences, which seemed to confirm the approach.
The problem? The ultimate aims of human life, and the goods of human behaviour, are derived not through empirical investigation but from what the human mind grasps of a non-empirical reality:
Humans are interpersonal beings that relate to each other through behaviour, and behaviour implies imperatives. i.e. How to behave? Empirical observation does not give us a guide on this matter. Since empirical observation can show us how best to achieve our goals but it cannot give us those goals in the first place.
This could be part of the reason why liberalism has become so dominant. What happens if there is held to be no valid way of knowing about ultimate human aims or moral goods? Then claims about such aims or goods will be reduced to the category of subjective opinion (or, perhaps, of mere sentiment). As the Social Pathologist puts it:
The traditionalist view was that the knowledge of these goals came from the non-empirical realm something the empiricists rejected. They had to place the locus of these goals in the mind or self. Morality becomes self-generated or self-optimised. Here are the seeds of moral relativism.
And here too perhaps are (some of) the seeds of liberal autonomy theory. If human aims and goods are particular to my own mind or self, rather than something grasped as part of a non-empirical reality, then the world becomes a radically individualised place, a place of wandering individuals seeking to follow their own self-generated good, whatever that may be.
The one overarching "common good" remaining is to leave people unhindered to follow their personal, subjective, self-generated good or to give people equal resources to implement such goods.
It's interesting to note too that some of the Western thinkers most associated with empiricism are also closely associated with liberalism (e.g. Locke and Mill). So it does seem as if the connection between empiricism and liberalism is worth pursuing.