[lendaddy]

My son (20 months) has done this for over a year. When he gets excited he raises his arms and shivers. This may be a little different, but maybe not. It does sorta look involunary but yet not quite. I'll admit it creeps me a little, but it shouldn't. It's funny to watch and you can tell (now) that it's a byproduct of his excitement but in the beginning it was weird.