Japanese Dating Statistic I

I pulled this from a book I’m currently reading:

A 2006 government survey—and note here that the government cares—found that 52.2 percent of single men and 44.7 percent of single women between the ages of eighteen and thirty-four had no relationship of any sort with any member of the opposite sex, not even friendship.

Source (in Japanese).

I couldn’t find a comparable statistic for single US adults, but I imagine that it’s a very different looking figure. Perhaps for people who attend all-boys or all-girls schools in the US, the lack of any relationship with the opposite gender would make sense, but the fact that even friendships do not exist seems rather shocking to me.

Is it due to the long hours that the Japanese often work that causes this to happen? Is it because of the herbivore man phenomenon in Japan that causes men (and women?) to be uninterested in talking with each other? Is this just shyness among singles in Japan taken to an extreme?

When I go to Japan this summer, I hope to be able to talk with some Japanese people about this figure. Obviously Japan’s population decline is a big problem; so what can we do to get Japanese people interested in each other?