Structural principles: Modifi cation, variation and extension of First Generation Actions

Nkosi (5 years 2 months 11 days) on Level 3 thrashes Manzu (5 years 5 months 8 days) below him on Level 2, semi-playfully, with a bunch of leaves, using a variety of arcs. Some of these actions are vertical arcs but he also changes position to make an upward, arcing swing instead of an overarm downward one. Manzu cringes below, but tolerates the rain of thrashes. He is a tough guy too and anyway knows his brother will not really hurt him.