By Mankular Lamin Gashnga
Consanguinity within the Khasi context is a highly developed and internally coherent social system. The term used for this formulation is rtap, a word widely employed in the War-Amlarem dialect. In standard Khasi usage, comparable terminology is rare. One notable instance appears in the writings of Radhon Sing Berry, who used the phrase “para ba ïabiang ka pylla” (“those who fall within correct relations”) when admonishing the observance of proper conjugal conduct. He further elaborated: “Wat ïapoi kha bad ki bym dei kynsi” – do not initiate conjugal relations with those who are not kynsi, that is, those who are not related in a manner analogous to brothers- or sisters-in-law, as such relations are taboo.
However, in Radhon Sing Berry’s usage, the term pylla functions primarily as a weighing scale/measuring rod, rather than as a formal system for calculating degrees of consanguinity. He did not develop it as a technical framework comparable to rtap. For the purposes of this article, therefore, I deliberately use the term rtap, as it more accurately captures the systematic reckoning of kinship relations and is academically equivalent to the widely used colloquial expression “kheiñ kur kheiñ kha” – the calculation of maternal lineage (kur) vis-à-vis paternal lineage (kha).
The Calculation of Rtap
The calculation of rtap may be broadly outlined through the following principles, which together define the permissible and prohibited degrees of conjugal relations within Khasi society:
1. Members of one kur may enter conjugal relations with members of another kur without reckoning consanguinity when the relationship is entirely new and when no prior conjugal relations have existed between members of the two kurs. Once such a relation has occurred, however, all subsequent relations must be reckoned on the basis of that first union, which becomes the foundational rtap. Conjugal relations are permitted only between persons related as bakha or kynsi.
2. Conjugal relations within the same kur are strictly prohibited, with no scope for pardon. Such violations risk snem (curse), social excommunication, or even exile (ksha).
3. Conjugal relations between persons who are neither bakha nor kynsi (meinah or panah) are forbidden and risk the imposition of sang (taboo).
4. Conjugal relations between paternal cousins are prohibited.
5. Certain affinial relations are also prohibited, such as between a man’s younger brother and the elder sister of his sister-in-law, or between a man’s elder brother and the younger sister of his sister-in-law.
6. Conjugal relations are normatively restricted to one man and one woman.
7. Marital or conjugal relations must be socially recognised and presided over by elders of the respective kurs.
8. Conjugal relations between a man’s maternal nieces or nephews (pyrsa kur) and his own children are prohibited during his lifetime (Hatdoh Lamin Pohsnem, unpublished MS.) – or, according to some oral traditions, for at least three generations, on the understanding that blood relations are still too close for healthy reproduction and hence to avoid what is termed kylliang khaw.
Taken together, these principles define the entire relational network among Khasi kurs. While the terminology used to describe these relations may vary across dialects, the underlying logic and social function remain consistent throughout Khasi society.
Multi-Stratum Kinship and Social Mathematics
It is important to emphasise that rtap is not a simple or dualistic system. It is fundamentally multi-stratified. Dr. Fabian Lyngdoh describes Khasi kinship as a triple-stratum relationship, noting that each individual simultaneously exists as kur, kha, and khun-kha. This triangular structure demonstrates that Khasi kinship is not a linear or two-way system, but a relational matrix in which identity and obligation are continuously recalculated.
In simpler terms, rtap functions as a social calculus that allows individuals to locate themselves in relation to every other member of society – to tip kur tip kha. It is a method of knowing where one stands socially, morally, and biologically. This is why rtap is best understood not merely as custom, but as a form of applied social mathematics.
Rtap, Religion, and Cultural Autonomy
Crucially, the reckoning of rtap is not religious in origin. It can be argued that traditional Khasi religion adapted itself to an already functioning system of lineage reckoning, and religious elements were incorporated into the moral framework only in later stages of societal development.
Neither had the widespread conversion of the Khasis to Christianity ever interfered with the foundations of the Khasi kinship system, despite the existence of biblical consanguinity laws – such as those found in Leviticus. This tacit acceptance suggests that the Khasi system is internally coherent and morally sufficient.
The calculation of rtap may therefore be regarded as an early and ingenious attempt at what we would now describe as a scientific approach to social organisation. Its foundational concern was the avoidance of incest and inbreeding. This is what I describe as social mathematics or mathematical sociology – a layered calculation (syrtap, tap, pylla) of blood relations designed to promote social stability and biological well-being.
Matrilineality, Cognatic Descent, and Consanguinity
While Khasi society is commonly described as matrilineal, it is incomplete as an explanation of Khasi consanguinity as blood relations are reckoned on both maternal and paternal sides. Paternal blood ties are not nullified; they are simply limited in generational scope.
In this sense, Khasi society is better described as cognatic rather than strictly unilineal. Consanguinity on the maternal side is perpetual, while paternal consanguinity extends only to a certain number of generations. Matrilineality thus functions primarily as an identity marker rather than as a denial of paternal kinship. This is also consistent with biological science, as a child inherits equal genetic material from both parents.
Rtap, Science, and Sociology
Academically, rtap is not a philosophy or belief system. It is a calculation science. It emerged through long-term observation, social trial and error, aimed at reducing disease, morbidity, and social disorder. Its guiding principle is straightforward: the greater the relational distance, the healthier the potential offspring.
Neither can it be equated with eugenics, as it is not grounded in ideological prescriptions of human worth but in practical social reasoning. Contemporary genetics itself acknowledges the limits of predicting health outcomes or guaranteeing freedom from genetic disorders. To dismiss rtap as “unscientific” is therefore to misunderstand both its function and its scope.
From a sociological standpoint, rtap performs a clear structural function. It regulates conjugal relations, maintains social boundaries, and historically contributed to physical and social well-being. In this respect, it offers a compelling example of ‘structural functionalism’, illustrating how cultural mechanisms evolve to meet essential societal needs.
Rtap, Non-Khasi Marriages, and the Role of Tang Jait
A critical question arises when a Khasi individual marries a non-Khasi. This is where the institution of Tang Jait – the adoption or formation of a new clan – becomes indispensable.
The Khasi Social Custom of Lineage Act, 1997 defines Tang Jait as a ceremony for adopting a Jait for persons born of a Khasi father and a non-Khasi mother who have been assimilated into the Khasi community. The ceremony may be performed according to prevailing custom by members of the father’s kur, in the presence of village authorities.
Tang Jait allows the rtap system to remain coherent within new family configurations. Without it, the entire calculus of consanguinity becomes ambiguous.
Institutional Negligence and Its Consequences
Despite its importance, there have been serious instances of institutional negligence regarding Tang Jait. The JHADC has failed to formally acknowledge or systematise this practice, despite historical and ethnographic evidence of its existence. This is because of claims that the so-called “Jaintias” are not Khasi and therefore there is no Tang Jait in the system. However, an elder of the Sari clan once told me in a very matter-of-fact manner that the Sari clan originated due to a non-Khasi mother. This is clear evidence that there is Tang Jait also among the Pnars. Moreover, numerous clans, including Bamon (Brahmin) and certain Dkhar clans, clearly imply non-Khasi maternal origins. Even today, new clans are formed ‘unofficially’ when Khasi (Pnar/War) men marry non-Khasi women. This reflects not a failure of tradition, but a failure of administration.
A second instance of negligence is visible in sections of the Christian Church. As mentioned in a letter to the editor ST dated December 8, 2025 by Bashanlang Kharumnuid, the suspension of the late Rev. G.P.L. Gadew, for offering prayers at a Tang Jait ceremony conducted under KHADC authority raises serious questions. If a Presbyterian pastor cannot pray for a Presbyterian family at a lawful customary ceremony, then the Church must clarify its position whether it is against Khasi custom and identity.
If either the JHADC or the Church rejects the legitimacy of Tang Jait, they are obligated to answer a fundamental question: to which kur should a child of a non-Khasi mother belong? Silence on this issue creates confusion rather than moral or cultural clarity.
Conclusion
Existing codified customary laws have yet to integrate comprehensive rules of consanguinity. As a result, many Khasis rely on informal knowledge transmitted by elders, leaving room for uncertainty and inconsistency. It would therefore be prudent for both traditional authorities and church institutions to formally incorporate Khasi consanguinity rules into educational, legal, and pastoral frameworks.
This article does not seek to condemn any individual or institution, nor does it claim absolute authority over Khasi custom. Its aim is to contribute toward a clearer understanding of rtap – a foundational yet under-examined system that continues to shape Khasi society. A deeper engagement with this system is essential if Khasi tradition is to evolve with clarity, coherence, and confidence.
