After 1935, some scientists made a lot of investigations and studies on the mystery of shrinking heads in South America with great interest. Among the outstanding achievements: 1947, the Norwegian scholar Thor Jardal ventured into the dense forests of Ecuador, and he described in detail the reduction of South America in his book Alone on a Raft Crossing the Ocean. According to him, an Indian living in the tropical forest of Kivito cut off the heads of other foreigners' enemies, smashed their skulls and dug them out, and then put hot sand in the hollowed-out scalp. After special design, the whole skull was reduced to the size of a fist, but its appearance remained unchanged, and it was preserved as a souvenir of victory. Some scholars believe that this statement and assertion are credible. In the warehouse of the National Museum of Anthropology and Archaeology in Peru, there are several reduced primitive heads, only the size of fists. One of them has a moustache, baldness and a full face of anger, which is very lively and interesting.

The mystery of skull shrinkage has high scientific research value and has attracted the attention of UNESCO. In the 1950s, UNESCO sent several famous scientists to the Andes for an in-depth investigation. They found dozens of caves more than a foot high on a rock covered with mang forest. There is a fist-sized head between the walls of each cave, which is not only complete in facial features, but also proved to be an adult's head by a series of tests such as scientists' physiological slices. These discoveries have attracted the attention of many scientists all over the world. The mystery of "Lilliput" shrinking has attracted more and more people's interest in the world.