Introduction
Lewis Henry Morgan, a foundational figure of classical unilineal evolution, laid the empirical and theoretical groundwork for anthropological kinship studies. Through his seminal works, 'Systems of Consanguinity and Affinity of the Human Family' (1871) and 'Ancient Society' (1877), he proposed that human social institutions developed along uniform, progressive stages driven by psychic unity and material technological progress.
Morgan's Evolutionary Framework
Morgan formulated an evolutionary progression linking technological advancement and property forms to social arrangements involving family, marriage, descent, and kinship terminologies.
- Evolution of Family and Marriage: Morgan posited an initial stage of 'primitive promiscuity' devoid of formal marital ties. Society progressed through five sequential forms of the family: Consanguine (incestuous group marriage among blood siblings), Punaluan (group marriage excluding brother-sister mating), Syndyasmian or Pairing (loose non-exclusive monogamous union), Patriarchal (polygynous family under male authority), and finally Monogamian (exclusive pair-bonding characteristic of modern civilization).
- Evolution of Descent (The Matriliny-First Hypothesis): Morgan argued that under conditions of initial promiscuity and group marriage, paternity was uncertain, making matrilineal descent the only viable way to trace lineage. However, with the emergence of pastoralism, agriculture, and private property, men sought to transmit accumulated wealth to their biological offspring, precipitating a structural shift from matriliny to patriliny.
- Evolution of Kinship Terminologies: Morgan bifurcated kinship nomenclature into two broad categories: Classificatory systems, which group lineal and collateral kin under common terms (interpreted as survivals of ancient group marriage), and Descriptive systems, which strictly separate direct lineal relatives from collateral relatives, mirroring the development of monogamy and private property.
Critique by Contemporary Evolutionists
While sharing Morgan's unilineal premise, several contemporary 19th-century evolutionists severely contested his substantive stages and evidentiary mechanisms:
- Edward Westermarck (Critique of Primitive Promiscuity): In The History of Human Marriage (1891), Westermarck rejected the assumption of an initial stage of sexual promiscuity. Drawing on biological analogies and comparative ethnographic data, he asserted that pairing monogamy was humanity's earliest and most enduring institution, necessitated by the prolonged vulnerability of human offspring and instinctive aversion to inbreeding (the Westermarck effect).
- Sir Henry Maine (Patriarchal Theory vs. Matriliny-First): In Ancient Law (1861), Maine posited that society originated not from matrilineal bands, but from agnatic, despotic patriarchal family units governed by the eldest male (patria potestas). Based on Roman, Hindu, and Celtic jurisprudence, Maine maintained that patriliny preceded other social configurations.
- John Ferguson McLennan (Critique of Kinship Survivals): McLennan disputed Morgan's assumption that classificatory kinship terms represented survivals of past group marriages. He contended that these terms were merely forms of courteous social salutation or status categories. Furthermore, McLennan identified female infanticide, scarcity of women, polyandry, and bride capture as the primary catalysts of kinship evolution, rather than the evolution of private property.
Methodological Limitations
Morgan's schema relied heavily on speculative conjectural history, inferring prehistoric realities from living non-Western societies. Additionally, it reflected Victorian ethnocentrism by framing Western bourgeois monogamy and patrilineal inheritance as the absolute apex of human cultural evolution.
Conclusion
Despite the rejection of unilineal determinism and the primitive promiscuity thesis, Morgan earned the designation of the founding figure of kinship studies. His crucial insight linking kinship and descent structures to changes in property and material subsistence profoundly shaped historical materialism, including Friedrich Engels' classic work, and established kinship as a core subfield of modern anthropology.