Dr Pickler's studies and teaching on babies developmental patterns has had a big influence on many people over the years. This website put out by the Pickler/Loczy Fund is a great place to learn about them.
Here is the shortest excerpt of it to give you an idea. "It is said that in Budapest, "Pikler babies" can be recognized even when they are older because they move with grace and freedom. Dr. Pikler believed this is because they were not sat up before they were ready to move into a sitting position on their own, were not walked by having their hands held but were allowed to learn to walk at their own pace, and were not strapped into swings and infant seats, but were allowed to move naturally and at will and freely and allowed to spontaneously follow their own in-born developmental time-table."