Do most of them act like that?
Depends on how they are raised. All of my Argentine Black & White Tegus act just like that.

Do they do better in groups from your experience?
Depends on the group. If you have hatchlings in a group with mellow, tame, calm tegus, the hatchlings will learn to be calm. If you have hatchlings in a group of jumpy tegus, the hatchlings will be jumpy.

Rick