For example, one older female Hajji said, "I had a very good experience with female Hajjis from Indonesia. They would make space for me whenever I was walking if I gestured for them to do so. One of them even gave me Vicks VapoRub when she found out that I had the flu."

The quote comes from "Estimating the Impact of the Hajj: Religion and Tolerance in Islam's Global Gathering," a fascinating paper put together by Case Western Reserve's David Clingingsmith and two Harvard scholars, Asim Ijaz Khwaja and Michael Kremer. (Thanks to the Economist's FreeExchange blog for the link.)

The annual Hajj -- in which around 2 million pilgrims assemble in Saudi Arabia each year to worship in Mecca and Medina -- is currently taking place. According to the authors, the result of the gathering could be a greater commitment to peace and tolerance in the Islamic world.

Our findings show that, despite pilgrims being past the age at which belief and identity are considered most malleable, the Hajj has quite a remarkable effect in shaping the views of Pakistani pilgrims. It induces a shift from localized beliefs and practices towards global Islamic practice, increases tolerance, and leads to more favorable attitudes toward women. We find no evidence that by raising cohesion within the Muslim community, the Hajj threatens non-Muslims. On the contrary, the Hajj makes pilgrims more peacefully inclined, and increased tolerance extends to adherents of other religions.

If that conclusion seems counterintuitive to the "Clash of Civilizations" crowd, well, the authors have rigorous survey data to back up their thesis. Each year, Pakistan holds a lottery to determine which lucky aspirants get one of the limited number of Hajj visas made available by Saudi Arabia. The authors conducted interviews with winners and losers both before and after the Hajj, in an effort to determine how attitudes changed as a result of the pilgrimage. The answer, in short, is that travel appears to be broadening. Exposure to difference breeds tolerance.

For example: "Hajjis are 22 percent more likely to declare that people of different religions are equal and 11 percent more likely to state that adherents of different religions can live in harmony."

Of course, it's important not to overstate the touchy-feely-ness of the pilgrimage. While the authors report that the numbers of respondents "willing to explicitly declare" that the "goals for which Osama bin Laden is fighting" are incorrect doubled, they also note that, nevertheless, more than 50 percent of the Hajjis believed the goals were correct, and about a third "agree with the methods bin Laden uses." Still, progress is progress!