At least once a day. More often in summer or if I'm doing sports that day. Vast majority of people I know the showering habits of are the same.

I can't speak for him, but I shower once a day. I enjoy feeling clean and not smelling. I also appreciate when others do the same.

The whole experiment seams to be about his ego, I wish he tried to gain more insight into other reasons people chose to stay clean enough to not offend their peers with their smell instead of just concluding:

"I felt myself standing apart from the sheep-like masses who had been led to confuse their wants and needs."

I can go for a few days without smelling too badly. But I usually shower everyday, because my hair gets greasy fast.