The population of Madagascar is very unevenly distributed on the surface of the island, overall with low density; in 1931 it resulted of 3,723,000 residents, that is – being the surface of the island of 590,000 sq km. – about 6 per sq. km, a very low average if compared to those of European countries. In the total figure, the residents of the central plateau, that is, the Hova and Betsileo, count for more than a million and those of the eastern coastal region for approximately 400,000.
According to ASK4BEAUTY, the population of Madagascar was originally divided into an infinity of small tribes or rather of families, absolutely independent from each other and each under the authority of its natural leader. But after the successive Arab, Malay and European immigrations, several of these families began to regroup under foreign leaders. These groupings have gradually taken a great development, especially after the century. XVIII, and seventeen main tribes were formed, of which the most important are: in the center of the island the Hova, the Betsileo and the Bara; to the north the Antankarana; to the east the Betsimisaraka, the Betanimena and the Antaimorona; to the south the Antanosy, the Antandroy, and the Mahafaly; finally to the west the Sakalavas. The name of Malagasy which is now given everywhere to the residents of Madagascar is of foreign origin.
This Malagasy population (a term that is usually applied to all the peoples of the island) is made up of two mixed racial types: one Negroid, the other analogous to the Malay type, of smaller stature, olive complexion, smooth hair. Anthropologists and ethnologists have asked themselves the problem of this population. The current opinion is that a Malaysian population has settled on a fund of African black population. But A. and G. Grandidier (father and son), whose work forms to this day the main documentary source on Madagascar, are of another opinion. They think that the entire population of the island, except for some minimal contributions, is of Indo-Melanesian origin, indicating with this term the whole of the melanoid populations from India to the Fiji Islands.
The Grandidier were above all induced to this conclusion by the ascertained unity of language throughout the territory of Madagascar and by the evident belonging of this language to the Maleopolynesian language family (see below, paragraph Language). The type of culture of the current Malagasy population (see below, Ethnology paragraph), a culture which as a whole seems to be quite Indomalesian, confirms the hypothesis of the Grandidier.
Three hypotheses are possible. According to the first (that of the Grandidier), the Indo-Melanesians favored by the sea currents would have landed on the island several times. Frobenius logically developed this hypothesis when he derived the Guineo-Congolese culture from Melanesia via Madagascar. The second hypothesis is that of a continental migration: an Indo-Melanesian current would have radiated from India both towards Africa and towards Oceania. But in such a case the Indomelanesian influence should not have nearly extinguished in the Congo and remained so alive in Madagascar, and, above all, some Negro elements should have passed from Africa to Madagascar together with the Indo-Melanesian elements. At least for the language this has not happened. The third hypothesis does not consider migration as the main factor; the races would have formed on areas that overlap one another, areas larger than those they currently occupy. Having the Indo-Melanesian race restricted its area, Madagascar would be comparable to a secondary pool of water that subsists while the main pool is drying up. However, if this hypothesis clarifies the racial problem, it does not do the same for the linguistic problem, since the current linguistic ties cannot go back to the origin of the common Negroid race. Perhaps it is necessary to admit, in the final analysis, a combination of different processes and phenomena, and that to an ancient racial formation common with the Indo-Melanesian area, there were occasional but repeated arrivals by sea.
With regard to the hypothesis of the Grandidier, Sera observed that if it is evident that on all coasts, especially on the eastern ones, the influence of immigrant crossings has produced appreciable alterations especially in the socially high strata of the populations, it is necessary to think that these immigrations occurred, for the most part, in relatively very close times (2nd millennium AD) and by very civilized peoples (Indians, Persians, Arabs, Europeans) and advanced in the art of navigation. First, that is, prior to any observation of anthropological facts, it seems hardly credible to Sera that a few dozen at most men, that is, how many could contain the ships of not very evolved peoples, carried by currents or winds to enormous distances from their countries of origin, most likely accompanied, even if they were, by very few women, could have given rise to 3 million and more individuals, as are the current Malagasy. What conclusions Sera came to on the basis of the observation of anthropological data is stated in the following paragraph.