The alliterative expression nature and nurture in English has been in use since at least the Elizabethan period and goes back to medieval French. The combination of the two concepts as complementary is ancient, galton was influenced by the book On the Origin of Species written by his half-cousin, Charles Darwin. The view that humans acquire all or almost all their traits from nurture was termed tabula rasa by John Locke in 1690. A blank slate view in human developmental psychology assuming that human behavioral traits develop almost exclusively from environmental influences, was held during much of the 20th century. The debate between blank-slate denial of the influence of heritability, and the view admitting both environmental and heritable traits, has often been cast in terms of nature versus nurture. These two conflicting approaches to human development were at the core of a dispute over research agendas throughout the second half of the 20th century. As both nature and nurture factors were found to contribute substantially, often in an extricable manner, in their 2014 survey of scientists, many respondents wrote that the dichotomy of nature versus nurture had outlived its usefulness, and should be retired. The reason is that in many fields of research, close feedback loops have been found in nature and nurture influence one another constantly. As in ecology and behavioral genetics, researchers think nurture has an influence on nature. Similarly in other fields, the line between an inherited and an acquired trait becomes unclear, as in epigenetics or fetal development. John Lockes An Essay Concerning Human Understanding is often cited as the document of the blank slate view. Locke was criticizing René Descartes claim of an idea of God universal to humanity. Lockes view was criticized in his own time. Anthony Ashley-Cooper, 3rd Earl of Shaftesbury complained that by denying the possibility of any innate ideas, Locke threw all order and virtue out of the world, Lockes was not the predominant view in the 19th century, which on the contrary tended to focus on instinct. The question of innate ideas or instincts were of importance in the discussion of free will in moral philosophy. In 18th-century philosophy, this was cast in terms of innate ideas establishing the presence of a universal virtue, during this time, the social sciences developed as the project of studying the influence of culture in clean isolation from questions related to biology. Franz Boass The Mind of Primitive Man established a program that would dominate American anthropology for the fifteen years. The tool of twin studies was developed after World War I as an experimental setup intended to exclude all confounders based on inherited behavioral traits, such studies are designed to decompose the variability of a given trait in a given population into a genetic and an environmental component
This chart illustrates three patterns one might see when studying the influence of genes and environment on traits in individuals. Trait A shows a high sibling correlation, but little heritability (i.e. high shared environmental variance c2; low heritability h2). Trait B shows a high heritability since correlation of trait rises sharply with degree of genetic similarity. Trait C shows low heritability, but also low correlations generally; this means Trait C has a high nonshared environmental variance e2. In other words, the degree to which individuals display Trait C has little to do with either genes or broadly predictable environmental factors—roughly, the outcome approaches random for an individual. Notice also that even identical twins raised in a common family rarely show 100% trait correlation.
The "two buckets" view of heritability.
More realistic "homogenous mudpie" view of heritability.