The Nature and Nurture of Morality

Select any two people at random from amongst the eight billion humans alive today, and you are likely to find a great many points of moral agreement alongside a similarly large number of moral disagreements. How is it that all of this moral universality and diversity exists? This question beseeches an exploration of nature and nurture.

Modern Dismissals of the Nature-Nurture Debate

Increasingly, however, scientists are prone to bristle at these two n-words. Of course, every trait is a product of complex interactions between genes and environments, and so biologists and psychologists who study the process of development assert that debates about nature and nurture are misguided.

Because developmentalists are experts in the processes that lead traits to unfold within individuals, they rightly point out that the moral sense is the result of myriad dynamic forces, ranging from the molecular to the societal, which bidirectionally interact across the lifespan. These scientists typically argue that the debate between nativism and empiricism should be fully done away with in the study of human morality, and that we should instead study how traits emerge from the process of development itself.

This perspective is entirely reasonable. Developmentalists are correct in saying that it is senseless to attempt to parse the intricate process of gene-environment interplay into discrete components. We cannot coherently say that a person’s moral sense is 60 percent due to their genes, for example. But developmentalists are wrong in concluding that we must therefore stop engaging with the nature-nurture debate.

Salvaging the Nature-Nurture Debate

When people talk about “nature” and “nurture,” they are not always aiming to understand the causal processes that lead traits to form within individuals. Many psychologists are instead interested in exploring the factors that contribute to similarities and differences in moral beliefs and behaviors between people in a particular society, or between disparate societies. These interests lend themselves to questions about the causes of variation.

To study variation, scientists look across individuals rather than within individuals. For example, behavioral geneticists aim to estimate the degree to which sharing genes or sharing environments predict similarities in moral tendencies, though little is currently known about the heritability of morality. In a much more extensive body of research, evolutionary psychologists and cross-cultural psychologists have explored how moral tendencies sometimes transcend cultural boundaries and how these tendencies are sometimes bound to cultural learning. These pursuits make it much more sensible to think about nature and nurture as separable components, though recent work on gene-culture coevolution has demonstrated how they are frequently entwined.

Uncovering How Nature and Nurture Impact Our Morality

To date, cross-cultural studies that have looked for the sources of universality and diversity in moral tendencies have led to important conclusions about the extent to which certain aspects of our moral sense are buffered against external factors such as ecology or religion. Some elements of moral psychology (like the tendency to morally praise cooperative actions and the desire to punish bullies) are robust in the face of tremendous social and cultural variation, which is one sense in which these aspects of morality can be said to be “innate.” (Other ways of thinking about innateness, like developing in the absence of learning, being present at birth, or being genetically encoded, are more riddled with contradictions).

Conversely, other elements of moral psychology (like the extent to which seeking honor gives rise to moralistic retaliation and the number of entities that are considered to be deserving of moral concern) vary widely across social and cultural divides, indicating that they are highly susceptible to external influences––not in the sense that environments play a “larger role” than genes in the development of these traits, but in the sense that variations in environments give rise to substantial cross-population variance in the manifestation of these traits.

The cross-cultural study of morality will continue to produce many crucial insights into human universals and human differences, and these findings will continue to give rise to theoretical accounts that fruitfully employ the constructs of nature and nurture. As research increasingly discerns the extent to which people from distant societies exhibit more similarities or more differences in their moral values and actions, psychologists will be increasingly able to draw reasonable conclusions about how nature and nurture influence our moral tendencies. The nature-nurture debate is certainly in need of refinement, but it should not be put to rest.