Yet they retain, together with these borrowed features, a sufficiently definite stock of original characteristics. Physically they differ much from Khasi and Assamese alike. Their social fabric is based upon clearly marked exogamous groups, with patriarchal principles of marriage and inheritance; they call these by a Khasi name (kur), but have no trace of the matriarchal family as known among the Khasis. They build their houses on posts, while their neighbours, except the Kukis, build on the ground. Their deities are of the primitive kind which is common to all Indo-Chinese races, well known, under the name of Nats, as the object of popular worship and propitiation in Burma.
Ever since the race has been studied, it has been noticed that it was difficult to establish its exact place and affinities in the heterogeneous congeries of peoples who inhabit the mountainous region between India and Burma. This was remarked by Robinson in 1841 and 1849, by Stewart in 1855, by Damant in 1879. At the Census of 1881 an attempt was made to bring the Mikirs into relation with the Boro or Kachari stock; but it was seen at the time that more must be ascertained regarding their neighbours before any final judgment could be arrived at. Dr. Grierson, on linguistic grounds, has classed them in the Linguistic Survey as intermediate between the Boro and the Western Nagas. It appears to the present writer, in the light of the much fuller information now available, that they should be classed rather with those tribes which form the connecting link between the Nagas and the Kuki-Chins, and that the preponderance of their affinities lies with the latter of these two races, especially those dwelling in the south of the Arakan Roma range, where the Chin tends to merge into the Burman of the Irawadi Valley.
When Robinson and Stewart wrote, it was still remembered that the Mikirs had once been settled in strength in the country (now called North Cachar) to the immediate north of the Barail Range, and in contact with the Angami, the Kachcha, and the Kabui Nagas; and that, exposed as they were in this locality to the inroads of the Angamis and the oppression of the Kachari kings, they had migrated westwards to the territory of the Jaintia Raja in search of protection. It was noticed in the Assam Census Report of 1881 that in this region north of the Barail, where there are now no Mikirs, local names belonging to their language indicated their former presence. When they lived there, they must have been in touch with tribes belonging to the Kuki-Chin stock, who have for centuries occupied the hill ranges to the south of the valley of Cachar, and the mountains between that valley and Manipur.