I've heard as children grow older and suddenly are no longer the center of everybody's world (I cry, someone picks me up, holds and feeds me and comes running serving my every need), they develop behaviors as they gradually learn to cope with this realization. I have no children but this sounds like a logical stage for a kid to go through....
Studies have shown that kids whose every need is met when they are very young are much more confident as they mature and assert their independence. So when Great Aunt Agatha (or whoever) tells you to stop picking up your child, or going to him/her when she cries because you will spoil them, there is documented research that that is not the case.