Nature versus nurture

The nature versus nurture debate involves whether human behavior is determined by the environment, either prenatal or during a person's life, or by a person's genes. The alliterative expression 'nature and nurture' in English has been in use since at least the Elizabethan period and goes back to medieval French.It is now clear that genes are vastly more influential than virtually any other force in shaping sex identity and gender identity…he growing consensus in medicine is that…children should be assigned to their chromosomal (i.e., genetic) sex regardless of anatomical variations and differences—with the option of switching, if desired, later in life. The nature versus nurture debate involves whether human behavior is determined by the environment, either prenatal or during a person's life, or by a person's genes. 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 (Greek: ἁπό φύσεως καὶ εὐτροφίας). Nature is what we think of as pre-wiring and is influenced by genetic inheritance and other biological factors. Nurture is generally taken as the influence of external factors after conception e.g. the product of exposure, experience and learning on an individual. The phrase in its modern sense was popularized by the English Victorian polymath Francis Galton, the modern founder of eugenics and behavioral genetics, discussing the influence of heredity and environment on social advancement. 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 behavioral traits from 'nurture' was termed tabula rasa ('blank slate') 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 widely held during much of the 20th century (sometimes termed 'blank-slatism').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 an ideological 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 inextricable manner, such views were seen as naive or outdated by most scholars of human development by the 2000s. The strong dichotomy of nature versus nurture has thus been claimed to have limited relevance in some fields of research. Close feedback loops have been found in which 'nature' and 'nurture' influence one another constantly, as seen in self-domestication. In ecology and behavioral genetics, researchers think nurture has an essential influence on nature. Similarly in other fields, the dividing line between an inherited and an acquired trait becomes unclear, as in epigenetics or fetal development. John Locke's An Essay Concerning Human Understanding (1690) is often cited as the foundational document of the 'blank slate' view. Locke was criticizing René Descartes's claim of an innate idea of God universal to humanity.Locke's view was harshly 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', leading to total moral relativism.Locke's was not the predominant view in the 19th century, which on the contrary tended to focus on 'instinct'.Leda Cosmides and John Tooby noted that William James (1842–1910) argued that humans have more instincts than animals, and that greater freedom of action is the result of having more psychological instincts, not fewer. The question of 'innate ideas' or 'instincts' were of some 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, prerequisite for objective morals. In the 20th century, this argument was in a way inverted, as some philosophers now argued that the evolutionary origins of human behavioral traits forces us to concede that there is no foundation for ethics (J. L. Mackie), while others treat ethics as a field in complete isolation from evolutionary considerations (Thomas Nagel). In the early 20th century, there was an increased interest in the role of the environment, as a reaction to the strong focus on pure heredity in the wake of the triumphal success of Darwin's theory of evolution. 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 Boas's The Mind of Primitive Man (1911) established a program that would dominate American anthropology for the next fifteen years. In this study he established that in any given population, biology, language, material and symbolic culture, are autonomous; that each is an equally important dimension of human nature, but that no one of these dimensions is reducible to another.