I taught for over 33 years and I've owned 4 iguanas. All but one have bitten me (the one female is the one that has never bitten me). I've had stitches, skin glue, surgery for a torn tendon and a black eye from my males. They react to colors you wear, changes in environment and breeding season.
They are gorgeous, magestic creatures. My advice is not to, for many reasons. A bearded dragon is a very good lizard pet. They like to be held, and don't pose the risk that iguanas do. When an iguana bites it feels like a combination between getting slammed in a car door and getting your hand in a sewing machine.