Culture in the western world in 2000 is way different than it was in 1900, just like culture in 1900 was a far cry from 1800. So by the year 2100, what will be the cultural norms? When will it be okay to reboot your sinuses in public and what will it be like as the teenager-ization of adults continues well into old age? What kind of etiquette will be required between humans and sentient humanoid robots? What will be the pressing social issues of the time?
Dressing up as animals, spirits, gods and ancestors is something that humans have been doing almost as long as there have been humans. And even in the developed, urbanized landscape of Europe, some of these ancient traditions still survive, ushering in solstices and equinoxes and harvests.
Right now, the jump-off point for all astronauts headed to the ISS is Kazakhstan, where the Soviet Union built their rocket launching site. Kazakhstan, though it was once part of the USSR, is quite different from Moscow. And when the astronauts of ISS Expedition 34 landed, they were greeted by women in traditional Kazakh dress. Because… Kazakhstan.