In short, Yes.
I know many people who SI.
Aliza, Tiffany, Brandon, Travis, Amber, and Jeannie, are just a few.
In all honesty, I don’t think they had any influence on me (as I was SI before I met Tiffany, Jeannie, Aliza, and Brandon) but that I had the influence on Travis and Aliza. Aliza has been my best friend since we were 11. I’d already been SI for about three years and Aliza was the first to know about it. Shortly after was when she began to cut herself with scissors for attention, yes, I believe that showing it to everyone you know and smiling proudly when you do it means you’re doing it for attention. She has recently stopped (SI stopped being cool).
Travis and I have known each other since second grade. Last year, he began to SI when ’emo’ became cool.
He literally came up to me one afternoon and showed me the cuts under his arm band and said; “Look! Look what I did! Now you have to show me yours. I want to see yours!” Me, pissed and embarrassed, smacked the shit out of him. To which he responded something like; “Ow! What the fuck!” I told him he had to stop or I would never speak to him again, he called me a hypocrite, I called him an asshole. He consented to stop, though, and he kept to his promise.
Person [female, age 16, began to SI at age 8, high school student]