Why do women go to the bathroom in groups?

Women go to the bathroom in groups today because they always have, it's still all about safety.

Back in the day when we were living in caves this provided safety from wild animals and strangers. Safely in numbers for women may go back thousands of years. Women have been gatherers since the beginning of time and I believe these early safety measures still influences their behavior today. Men on the other hand, have different plumbing and can relieve themselves in short order. Women need to take a moment and stoop down and in doing so would have put themselves in more danger while they are off balance.

So guys, when you are out for the evening and see a group of ladies going off to the powder room together you tell the men left behind that the ladies are still behaving like they did thousands of years ago.

This is an example of why we still behave like hunters and gatherers even today

The Kitchen Table Anthropologist