I'm with him 24/7, he's never been babysat, and doesn't attend daycare. I can say with 100% certainty he's never been dropped or anything.

Today I went to lift my 13 month old into the air above my head and he got a really scared look on his face and started grasping at my shirt. When I threw him in the air, he did laugh a lot like normal, but had a slightly scared look on his face on the way up. He enjoyed and was not scared of being held upside down from my waist, which you'd think would he scarier than being right side up?

He hasn't fallen from any high height. The only fall he's had recently at all was earlier today when I opened my door to come in from taking the garbage out and didn't realized he was standing with his hands on the glass.

I have a 4 y/o and a 2 y/o, neither of whom suddenly developed a fear of being held up high/thrown in the air.

Is it normal behavior to suddenly develop a fear like this? Obviously, I'm not going to hold him over my head anymore even though he used to enjoy it. It's no skin off my teeth if he doesn't want to do it anymore. Just wanted to make sure this kind of thing is normal? I will be asking at his 15 month appointment, but that is in September.