Hajj makes Muslims more tolerant, study suggests

I haven't read the paper so I can't say anything about metodology and scientific consistency.
Generally speaking it seems reasonable.

In her book l'Enracinement(The Need for Roots: Prelude to a Declaration of Duties Toward Mankind) Simone Weil suggested that once the war would be over, the government should have looked for ways to provide stimulus to the farmers giving them the chance to visit other regions of the country, to share experience with colleagues and share a more general sense of purpose that will give them strenght in the solitude of their life.

The "slightly different" is a powerfull agent of change, especially in conservative societies.

Here's the article.