Why social science?

At times I question the way design and the social sciences become bed fellows in the world of technology research. But when I read this (which i'll post on in more detail soon), it all makes absolute sense. To quote;

I have what I think is a pretty good test of whether a person is a social scientist or not: do they eavesdrop on a fairly regular basis on other people’s conversations on trains and planes, on buses, in the street, and so on? If they don’t, I suspect that they really want to be a philosopher or an architect – or both.

I think being an eavesdropper is a solid trait of any designer worth their salt.