Kouori were sculptures of athletic young men made according to guidelines that had been the accepted convention for many decades. A 'standard' kouros would look much like any other: its feet would be pointed straight forward, with the left in front of the right, its arms would rest at its sides, and its posture would be erect and disciplined, probably intending to illustrate superiority and confidence.

Around 490 BC in Athens, the fledging democracy started to produce something quite new to Greek sculpture, illustrated by the famous Critius Boy statue. Unlike the kouroi, this new style of sculpting sought to portray a different sort of man - one that was both more dynamic and more realistic - the sort of person who reflected more accurately the diversity and complexities of being a democratic citizen. Within only a few decades this new style would overtake the rest of Greece, rendering existing styles almost obsolete.