Test 1 Study Guide Chapter 2 In February 2001 scientists published a map of the human genome the complete set of genes for building and operating a human body Focus on 4 main questions to answer what makes development happen o How are ideas about nature and nurture changed o What are genes What exactly do they do o What is the environment o How do the genetic code and environmental contexts interact in development Perspectives on Nature and Nurture o 4 main views Development is driven by nature Nativism the idea that intelligence and other characteristics are innate or inborn not acquired or learned Preformationism 17th century o Prevailing view was that the embryo was pre formed a miniature adult whose future anatomy and behavior were already determined o Belief of Preformationism was accompanied by beliefs about human nature Rousseau s Innocent Babes o In general Western culture has viewed children as innately bad o Was an exception believed children were innocent at birth and develop according to nature s plan like a flower o The environment matters but nature plays a leading role o Parent s job is to protect the child from harmful interference and let the child s development unfold Genetic Determinism and Eugenics o Genetic determinism the idea that human qualities are genetically determined and cannot be changed by nature or education Internal natural genetic factors control development and external nurturing environmental factors have little impact the complete individual is already present in the fertilized egg o Eugenics good genes a philosophy that advocates the use of controlled breeding to encourage childbearing among individuals with characteristics considered desirable and to discourage childbearing among those with undesirable traits Best known example is Hitler s effort to purify the Aryan race Development is driven by nurture Environmentalists hold that the newborn is uninformed like a lump of clay and the individual s characteristics are entirely the product of experience upbringing and learning The Blank Slate o Introduced by John Locke in his essay Concerning Human Understanding o Locke argued that the infant s mind is a tabula rasa or blank slate stating that nothing about development is predetermined and everything the child becomes is a product of his or her environmental experience o Social consequence was the mental hygiene movement advocates of mental hygiene took the environmentalist view Watson s Behaviorism o Watson s theory on behaviorism was essentially a revival of Locke s tabula rasa a strict fundamentalist version of environmentalism o Anyone can become intelligent if they are rewarded for studying or learning and for solving problems with intellect rather than emotions nurture is everything Development is part nature part nurture How much does each contribute to different traits Heritability o The degree to which different traits are influenced by genetic factors o Heritability quotient o Studies of heritability Twin studies took advantage of a natural experiment Identical twins vs Fraternal twins Identical twins are more alike than fraternal twins Adoption studies compared adopted children to their adopted parents and biological parents Family relatedness studies studied blended families Concluded that virtually all human traits physical intellectual social emotional etc have substantial heritability quotients o Shared environment the environment that children growing up in the same household have in common o Nonshared environment the environment that children growing up together don t share o Key factors Genetic and environmental influences work hand in hand The idea that genes have the same impact in all environments is questionable Heritability estimates do not consider malleability even genes are flexible o Every aspect of development is the product of both biological and environmental factors Development results from the interaction of nature with nurture The contemporary view of nature and nurture emphasizes interaction The key to development is how genes and their environment interact Darwin s Influence o Believed that living plants and animals were descended from earlier simpler forms o Theory of evolution rests on 2 main ideas Survival of the fittest organisms best adapted to their environment survive Natural selection over time adaptive traits become passed on while others die off Epigenesis o Gradual process of increasing complexity due to interaction between heredity genes and the environment o Nothing or very little is predetermined o Rooted in embryology and the theory of evolution o G Stanley Hall first president of the APA believed that the early life of the individual resembled the evolutionary history of the species o Stem cells primitive undifferentiated cells found in large numbers in the embryo demonstrate epigenesis What Are Genes and What Do They Do o Genes provide the continuity that make us human o Direct the cells of an embryo to become a human being o Help to establish our common modes of thinking feeling acting and communicating o Contribute to the wide diversity within the human species o Study of human genetics deals with 2 different related questions How do genes make us human and distinct from other species Within this human pattern how do genes influence individual differences o Becoming Human All human beings have some traits in common Bipedalism walking upright on 2 feet Handiness opposable thumbs Language Ability to alter our surroundings Knack for calculations Self awareness Canalization the degree to which an element of development is dictated by the genetic program that all humans inherit Locomotion is highly canalized Development of morality is less highly canalized One distinctive feature of human development is that we are born prematurely Humans have evolved to be highly social animals a prolonged period of juvenile appearance behavior promotes the development of social bonds by attracting caregivers to infants Humans depend on learning more than other species do Our immaturity at birth make us more receptive to environmental influence Human Genome Project has show that we share some of our with even the simplest organisms o Human Diversity The nucleus of almost every human cell contains 23 pairs of chromosomes long strands of DNA The rungs of the DNA ladder consist of 4 chemical bases o Adenine Thymine o Guanine Cytosine Order of base pairs determine genetic instructions Chromosomes direct activity