The next step is elaboration, where new skills are added. This is followed by a period of stagnation, followed by a phase in which a novel skill emerges which is more advanced than the others. This novel skill then pulls the other skills along with it in a phase called reversion.
The subsequent stage is expansion, where new abilities are incorporated. This is followed by a period of stagnation, followed by a phase in which an innovative skill emerges that surpasses the others. This novel skill then draws the other skills along with it in a phase called reversion.