One of the hundreds of elongated skulls that were discovered in 1928 at Paracas Peninsula in Peru. Cranial deformation was practiced by the Paracas civilization (800-100 BCE) by tightly wrapping the head in cloth, during the first few years of life, in order to elongate the cranium
Talking out my ass here so please research and verify, but at least for the woman with elongated necks, it was originally to make them unattractive to men of other tribes. Over time, this turned into a specific beauty standard for their own tribe.