I'm new here. I felt compelled to register because this community seems so open and non-judgmental!!
I have mild versions of Xylophagia, Trich and OCD. I recently started looking into this after I sat at my desk and noticed a little clump of paper confetti that had fallen out of the hole punch. Without even thinking about it, I picked it up and at it. Then, as I sat there softening the tiny confetti paper in my mouth... I started peeling and eating the skin that was coming off my sunburn.
I do the "strangest" little things... but in mild forms. I love the feeling of pulling out my hair. I only do it to about 10 hairs on my head... always the same ones. As soon as they're 1 inch long and sticking straight up from my ponytail or through my bangs... OUT THEY COME! I always thought it was the feeling of the hair coming out that was the biggest "rush" for me... but realize that I actually bite off any goo that comes with it! Here's the funny part - I have OCD. I have so much need to control how I look/my hygiene, I only allow myself to pull those few hairs!! I also pull my eyebrows.. the same few everytime. I don't continue doing it until I have bald spots because then my eyebrows wouldn't look so pretty. I bit off the skin on the corners of my nails, but only enough to satisfy the urge because I don't want anyone to notice I do it and would never let it show "red" marks.
I've recently read that there might be some correlation between my OCD and Xylo/Trich ... I guess mine is more a mixed bag of PICA. I also have some mild control over my OCD - I still count, organize, balance things... but I choose which things to do it with. Toilet paper hangs over the roll... my closet is colour coded... my spice cupboard looks like a chinese army... my filing is done as I work... and when I'm really stressed, nothing gives me more pleasure then buying a box of Smarties and lining them up according to their colour by rainbow order.
I also have mild dyslexia.
Anyone else see a correlation between their disorders?
Anyone ever hear of a study that tries to figure out why we do what we do? Like a previous poster said, we're not hard-wired to do these things and they're definitely not learned, yet we do them all in the same manner for the same pleasure... the human brain is an amazing thing

PS: I feel really sorry for the posters that cannot control the pulling whatsoever. It's rather heartbreaking for me to hear!