In Japan, around the same time, the tradition of dyeing with black paint spread and not interfering with the development of caries. Black teeth were considered a symbol of wealth and matrimonial fidelity, and later this tradition spread to other peoples of Asia.
Similarly, according to Velasco, scientists have long believed that the Incas deformed the skulls of their children, pulling them out and turning their owners into "newcomers" for social reasons, but their specific motives remained a mystery, as there were almost no written descriptions of this tradition.
Velasco and his team uncovered one of the possible reasons for its appearance, having studied several thousand similar "skulls of strangers" and bodies of ancient Indians found in burial grounds in the Kolka valley, one of the first provinces of the Inca empire, which was peacefully annexed to it in the early 14th century by our era.
At the time, according to the chronicles of the conquistadors, two large tribes of Indians lived on the valley territory - collagua and cabana, each of which had its own cultural traditions, including "skulls". For example, in collagen junkyards, long elongated skulls are most common, and in cabanas tombs there are wide and "flat" cranial boxes.
Studying how these traditions changed in different epochs, Velasco and his colleagues hoped to find out what made the Indians invent this practice and what role it played in their lives. The matter is that some archaeologists believe that this tradition could be "brought" to the region by the Incas, who wanted to increase the feud between cabanas and collagua and force them to join the empire.
Archaeologists from the United States checked whether this was the case, comparing how the shape of the skulls of the nobility changed from that and from another tribe for several centuries, beginning with the 14th century and ending with the era of the fall of the Inca empire. As it turned out, this tradition was not a product of the "sabotage" of the Incan intelligence services, but a consequence of growing social inequality and stratification of society, as well as attempts by cabanas and collagua to unite in the face of the threat of the conquest of their valley by the forces of the neighboring empire.
This, in particular, was manifested in the fact that the number of "alien" skulls gradually grew - from 39% at the beginning of the 14th century and up to 74% at the time when the Kolka Valley became part of the Inca empire. In addition, both tribes developed a common standard of deformation of skulls, and gradually all differences in their practices disappeared.