The evolution of Greek sculpture has been relatively long and quite dramatic. Taking its roots in ancient Egyptian stylization, and evolving into naturalization and clarity of human form, Greek sculpture has made an enormous impact of the art of modern day. The early kouros figures were very similar to the ancient Egyptian male figures. For example the New York Kouros has many of the same characteristics of the Egyptian Menkure.
Both are in a stiff frontal pose, hieratic scale, both have the left leg forward, but there is no shift of body weight, and both have their arms down at their sides with clenched fists. Unlike the Egyptians, the New York Kouros, as well as all other archaic sculptures, had what is known as the "archaic smile", which was thin-lipped. The kouros figures were also given hair, which was very helmet like, and not very realistic.
On the other hand, the body of the early kouros figure was more naturalistic than ever before. They had a very slight roundness to the muscles, as apposed to the rectangular body forms of the Egyptians; this made them appear more life like and energetic. The shift from the archaic period to the Early Classical period introduces a technique or idea that changed sculpture forever.
This idea was called Contrapposto, which meant a weight shift of the body, creating movement, and naturalism. The Kritios Boy is a good example of this change in style.He stands on his left leg, with his right leg extended. This is true also for the New York Kouros, however the Kritios Boy has a weight shift that the New York Kouros does not. Kritios Boy is resting his weight on his left hip and leg, and his head is slightly turned to the right, which creates movement.
Another change between the archaic period and the Early Classical period is the loss of the Archaic smile. Kritios Boy is portrayed with a serious, unsmiling face. His hair has been cut short, but is still fairly helmet like. His musc..