Breaking down the question
The question has two demands. First, a conceptual distinction between natural and social inequality. Second, illustration of that distinction through the caste and class dimensions. Both must be addressed; an answer strong on theory but thin on examples, or vice versa, is incomplete.
The examiner wants you to establish that natural inequalities arise from biological or physical differences, whereas social inequalities are humanly created and institutionalised through unequal access to valued resources. The examples from caste and class should then show how social systems convert or overlay natural differences into structured, enduring hierarchies. Keep the theoretical part tight so there is room for concrete illustration.
How to approach it
Open with Rousseau's classic distinction: natural or physical inequality is established by nature — differences of age, health, bodily strength and mental capacity — while moral or social inequality is established by convention and consent, consisting of differences in wealth, honour, power and privilege.
Stress that sociology is chiefly concerned with social inequality, because it is patterned, institutionalised and reproduced across generations, whereas natural inequality is individual and does not by itself create hierarchy. Then illustrate through caste, an ascriptive and closed system, and class, an achievement-oriented and relatively open one. Our notes on concepts of stratification develop the typology. Conclude by noting how social systems often disguise their inequalities as natural.
Model answer
Natural inequality refers to differences among human beings that arise from nature — variations in age, sex, physical strength, health and innate ability. These differences are individual, biologically given and universal. Social inequality, by contrast, refers to inequalities created and sustained by society: the unequal distribution of wealth, power, status and opportunity, organised into enduring structures. Rousseau drew this distinction sharply, calling the first physical and the second moral or political, established by convention. The decisive point is that natural differences do not, of themselves, produce hierarchy; it is society that assigns them meaning, ranks them and attaches rewards to them. Sociology therefore concentrates on social inequality, because it is patterned, institutionalised and reproduced over generations.
Caste illustrates social inequality in its most closed form. Caste rank is ascribed by birth, fixed for life, and hedged by rules of endogamy, commensality and hereditary occupation, legitimised traditionally by notions of ritual purity and pollution. A person born into a particular caste inherits its status regardless of individual talent or effort. The inequality is wholly social — no natural difference explains why one group is deemed pure and another polluted — yet it is presented as part of a sacred, quasi-natural order. Andre Beteille's work shows how such ascriptive hierarchy resists mobility.
Class illustrates social inequality in a more open form. Class position rests on economic factors — ownership of property, market position, income and occupation — and is, in principle, achieved rather than ascribed. Movement between classes is possible through education, enterprise or changing economic fortune, so the boundaries are more permeable than those of caste. Yet class too is thoroughly social: the child of a wealthy family enjoys advantages of capital and connection that have nothing to do with natural endowment, so inequality is reproduced even without formal barriers.
Both dimensions confirm the central sociological insight: enduring human hierarchies are social constructions, frequently dressed up as natural to make them appear inevitable and just.
Examiner's perspective
The examiner is testing conceptual clarity and the ability to ground it in Indian social reality. A common failing is to treat all inequality as social without acknowledging the natural category the question names, or conversely to blur the two.
The best scripts open with a precise Rousseauian distinction, stress that natural difference becomes hierarchy only through social ordering, and then deploy caste and class as contrasting illustrations — caste as ascriptive and closed, class as achievement-based and relatively open. A concluding observation that social systems tend to naturalise their inequalities, presenting the humanly made as god-given or biologically fixed, demonstrates the analytical depth examiners look for at this level.