Research conducted using the Migrant Acceptance Index, a metric developed by Gallup to assess the emotional impact of immigration on both migrants and native-born populations, found that newcomers to countries with the lowest migrant-acceptance scores rated their lives more positively than did native-born residents, but this positivity faded the longer migrants stayed. In countries with high acceptance scores, longtime migrants expressed more optimism about the future than either native-born residents or newly arrived migrants.

While conducting research in the remote Iranian region of Khuzestan in the 1970s, folklorist Grace Goodell found that villagers refused to hunt any “unusual” migratory birds that stopped in the area for only a few days, believing them to be performing a hajj pilgrimage. Based on migration patterns, the birds may indeed pass over Mecca on their way to Africa, Goodell noted, although “probably few actually winter by the house of God.”