A really excellent post by Rich Armstrong. Two tremendous lines:
When our office culture is focused on business rather than socializing, we reduce the number of ways in which we all have to be the same. When we do that, we allow diversity to flourish.
If you want to build an inclusive culture, build a minimum culture. Build it around professionalism, boundaries, and work-life balance. Make sure your senior staff walks the walk, and spreads the word.
In my terms you want a narrow and deep culture, focused tightly on the work, and not a wide and shallow culture, focused on extracurricular and extraneous principles.