Final answer:
The thirty retired people on a two-week European tour are an example of a cohort, which is a group sharing a demographic trait. This social formation relates to both the historical concept of the Grand Tour and the continuity theory in the context of aging.
Step-by-step explanation:
The thirty retired people who go on a two-week tour of Europe together are an example of a cohort. A cohort is a group of people who share a statistical or demographic trait, such as age or the experience of retirement. This aligns with the continuity theory, which indicates that the elderly make choices to maintain consistency in both internal structures like beliefs, and external structures, such as relationships, aiming to stay active and involved throughout their elder years.
Relating this to historical context, the concept of traveling through Europe for educational or cultural enrichment dates back to the tradition of the Grand Tour, which was an educational trip undertaken by young men and women of high social standing. While the modern tour this cohort is on is for pleasure rather than education, it is reminiscent of historical travels that also served as a rite of passage and cultural exposure.
Modern groups of elderly tourists like our example create their own subculture, which can be seen as a form of Rose's subculture of aging theory. They often share common backgrounds and interests, developing new patterns of interaction within the group, much like the Grand Tourists of history did with their traveling companions and entourage.