Motivations and theories
One modern theory is cranial deformation was likely performed to signify group affiliation, or to demonstrate social status. Such motivations may have played a key role in Maya society, aimed at creating a skull shape that is aesthetically more pleasing or associated with desirable cultural attributes. For example, in the Na'ahai-speaking area of Tomman Island and the south south-western Malakulan (Australasia), a person with an elongated head is thought to be more intelligent, of higher status, and closer to the world of the spirits.
Historically, there have been a number of various theories regarding the motivations for these practices.
It has also been considered possible that the practice of cranial deformation originates from an attempt to emulate those groups of the population in which elongated head shape was a natural condition. The skulls of some Ancient Egyptians are among those identified as often being elongated naturally and macrocephaly may be a familial characteristic. For example, Rivero and Tschudi describe a mummy containing a fetus with an elongated skull, describing it thus:
the same formation [i.e. absence of the signs of artificial pressure] of the head presents itself in children yet unborn; and of this truth we have had convincing proof in the sight of a foetus, enclosed in the womb of a mummy of a pregnant woman, which we found in a cave of Huichay, two leagues from Tarma, and which is, at this moment, in our collection. Professor D'Outrepont, of great Celebrity in the department of obstetrics, has assured us that the foetus is one of seven months' age. It belongs, according to a very clearly defined formation of the cranium, to the tribe of the Huancas. We present the reader with a drawing of this conclusive and interesting proof in opposition to the advocates of mechanical action as the sole and exclusive cause of the phrenological form of the Peruvian race.
P. F. Bellamy makes a similar observation about the two elongated skulls of infants, which were discovered and brought to England by a "Captain Blankley" and handed over to the Museum of the Devon and Cornwall Natural History Society in 1838. According to Bellamy, these skulls belonged to two infants, female and male, "one of which was not more than a few months old, and the other could not be much more than one year." He writes,
It will be manifest from the general contour of these skulls that they are allied to those in the Museum of the College of Surgeons in London, denominated Titicacans. Those adult skulls are very generally considered to be distorted by the effects of pressure; but in opposition to this opinion Dr. Graves has stated that "a careful examination of them has convinced him that their peculiar shape cannot be owing to artificial pressure;" and to corroborate this view, we may remark that the peculiarities are as great in the child as in the adult, and indeed more in the younger than in the elder of the two specimens now produced: and the position is considerably strengthened by the great relative length of the large bones of the cranium; by the direction of the plane of the occipital bone, which is not forced upwards, but occupies a place in the under part of the skull; by the further absence of marks of pressure, there being no elevation of the vertex nor projection of either side; and by the fact of there being no instrument nor mechanical contrivance suited to produce such an alteration of form (as these skulls present) found in connexion with them.