Concrete is different than Formal. As human brains develop we are more able to produce and understand formal ideas, i.e. abstractions.
If an adult is, for whatever reason, not at the formal stage of mind function, for all practical purposes is like a child. Children have to be respected, but they cannot make decisions that affect all of us.
Maybe there are further stages, I pose that, scientists are either at the formal stage, or something even more advanced.
Scientists have to see what others do not see.