When children realize that rules are created and agreed upon cooperatively by individuals and can change if necessary, this development is known as:​

Agroup of engineering students from purdue university reported that its licking machine, modeled after a human tongue, took an average of 364 licks to get to the center of a tootsie pop. twenty of the group's volunteers assumed the licking challenge-unassisted by machinery-and averaged 252 licks each to the center.