I thought the same thing when I filled out my apps. I had research and volunteering at a hospital, but not much else...no clubs, no Frat. I guess my advice to people is to find some clubs. Most of them really demand very little time. At ICO I belong to several different clubs and organizations, and unless you are an officer (which I am of one of them), they only involve you coming to speakers and social events.
Not having much extra curr. wont destroy your application if you have decent numbers, but having them can help. They are not going to say,"S/he has good numbers and they did will in the interview...but s/he was not a member of the gleek club...REJECTED!!!" 😱
GOOD LUCK!