It's more than just a habit; I can tell you that much. I guess you have to have been a sufferer to fully understand. My trich was really bad all the way up til middle school when I started other treatments and such. I had a big bald spot on the top of my head and I also used to pull under my bangs and the hair near my neck where no one could really see. It's not like a habit where you just try it a couple times consciously and get adapted to it, it's a physical impulse that's extremely hard to resist and doesn't have to wait at least 30 days to fully form.

As far as what it includes, I agree with Lynn P. It's the impulsive pulling of hair.