Hmmm. New research seems to suggest that human settlements predated agriculture, perhaps by a long time. Permanent hunter-gatherer settlements at Ohalo II in Israel (23,000 years old, with huts made from brush plants), as well as the Natufian settlements in Jordan and Israel (14,000 years old) strongly predate the first agriculture (currently dated 11,500 years ago in the Levantine Corridor).
If hunter-gatherers were living in permanent settlements for a long time before agriculture, we have to ask why. Agrilculture has generally been presumed to be the answer, not some Johnny-come-lately.
Ian Hodder, dig leader at Çatalhöyük in Turkey has suggested that the residents there settled due to religious convictions. That is particularly interesting, since Joseph Campbell has told us that those societies were almost certainly maternal and worshipers of the lunar bull cult (a flavor of earth goddess worship).
Could it be that women caused the first human settlements to occur and agriculture came later, to help feed people who were already stuck in one place? That would certainly explain a lot, especially the population explosion dates and the lack of significant climate change in the Fertile Crescent. If so, human settlement would be the first, and perhaps most important, of the Big Memes.