Genetic and Environmental Factors of Intelligence One of the most interesting and controversial areas in behavioral genetics, human intelligence is currently assumed to be subject to both genetic and environmental influences. While this assumption is accepted by a majority of geneticists and behavioral scientists, there is great disagreement on the degree of influence each contributes. Arguments for environmental influences are compelling; at the same time there is growing evidence that genetic influence on intelligence is significant and substantial (Eyesenck, 1998; Mackintosh, 1998; Plomin, 1994; Steen, 1996). The purpose of this paper is to explore the question: "How is intelligence influenced by heredity and environment?" …show more content…
His concept involved the idea that certain mental tasks are appropriate to certain ages, such as the ability to recite the names of the months: while expected of a ten year old, such ability would be rare in a three year old. Binet quantified intelligence as the Intelligence Quotient (IQ): the ratio of mental age to chronological age, multiplied by 100. Reasoning that low intelligence stemmed from improper development, Binet envisioned the test as a first step in treatment: a diagnostic instrument used to detect children with inadequate intelligence in order to treat them using "mental orthopedics." Binet argued forcefully against the idea that intelligence is fixed or innate: "We must protest and react against this brutal pessimism (Lewontin, Rose, & Kamen, 1984)." However, those who translated his test into English tended to disagree, arguing that the test measured an innate and immutable, genetically inherited characteristic. After Binet's death in 1911, the Galtonian eugenicists assumed control, shifting the focus firmly toward genetic explanations by insisting that differences in intelligence between social classes and races were due to inherent genetic differences. Over time, the tests were standardized to correspond to a priori conceptions of intelligence by including items that correlated well with school performance. Test items that differentiated between gender
Throughout the history of human existence, there have always been many questions that have plagued man for centuries. Some of these questions are “what is the meaning of life” or “which came first, the chicken or the egg.” Within the last 400 years a new question has surfaced and has caused an enormous controversy which takes our minds to much further levels. The controversy is whether inherited genes or the environment influences and affects our personality, intelligence, behavior, development and abilities. This controversy is most often recognized as the “Nature vs. Nurture” conflict. Some people believe that it is strictly genes that affect our ways of live and how we are, while others believe that it is the environment that affects
The brain is one of the most complex, unknown organs of the human body. Researchers often break down the characteristics of the brain to whether tendencies are achieved through nurtured environments or the inheritability of genetics. Intelligence is one of the most controversial topics when it comes to deciding whether environment or genetics are most influential. Many argue that intelligence is based on environmental factors and the unique ability to work hard, but fail to realize the essential cognitive qualities concerning what truly defines intelligence. Although some may consider this trait as based on environment, intelligence is a cognitive attribute established by the nature of genetics.
Human behavior is a loosely defined foundation for individuality, generally considered to be influenced and developed by the environment. However, recent molecular studies have exposed genetic factors that suggest a more biological origin for behavior. Gene segments in the genome of humans and other animals have been identified and associated with particular behavioral traits. Is it possible that the presence or absence of even a single gene may predispose one to alcoholism, increased irritability, or enhanced intelligence? Clearly exploration of the nature versus nurture argument with regard to genetic predisposition has social, political, and legal significance.
intelligence is determined by environment or genetics. The fact that human DNA is nearly identical across
In the beginning of the 20th century, French psychologist Alfred Binet developed an intelligence test to pilot student achievement. Since then, a plethora of tests of similar rigor have emerged throughout the world; however, when looking towards the United States, it is apparent that these tests are in favor. In the United States, standardized tests have been a part of student life for more than 50 years (Fletcher). The problem arises in the sense that these tests are now more pressure-packed and ubiquitous than ever. This can be linked to the fact that in the U.S., students are now taking more standardized tests than ever before.
The biological approach in psychology states that behaviour is determined by a genetic component which results in a particular trait or behaviour. A topic area within psychology where this can be investigated is the heritability of IQ, it is suggested that genetic influence is the only factor to consider when investigating IQ, however others have suggested that other factors may play a role in determining IQ.
Such findings and the current state of the emerging field of behavioral genetics are summarized by the distinguished academics Cynthia Coll, Elaine Bearer and Richard Lerner, editors of the compendium Nature and Nurture: The Complex Interplay of Genetic
There is also scientific opinion that intelligence is attributed to DNA passed on from your parents. ( Plomin , Spinath 2004)
Alfred Binet (July 11, 1857 – October 18, 1911) was a French psychologist who invented the first usable intelligence test, known at the time as the Binet test and today referred to as the IQ test His principal goal was to identify students who needed special help in coping with the school curriculum. Along with his collaborator Théodore Simon, Binet published revisions of his intelligence scale in 1908 and 1911, the last appearing just before his death. Binet was born as Alfredo Binetti in Nice, then part of the Kingdom of Sardinia. He was the only child of a physician father and an artist mother. His parents separated when he was young, and Binet then moved to Paris with his mother. He attended law school, and earned his degree in 1878.
The debate surrounding the heritability of intelligence is one that has been going on for centuries starting with Sir Francis Galton in 1869 and the publication of his book, Hereditary Genius. Galton was one of the first scientists to study individual differences in intelligence. In his book, he claimed that intelligence is inherited and that this is supported by the fact that eminence runs in families. He went further to say that selective breeding ought to be encouraged in order to improve society which sparked the on-going controversy surrounding
Much like Binet, Wechsler believed that intelligence involved different mental abilities. So Wechsler decided that rather than scoring the test based on
The nature versus nurture debate is the scientific, cultural, and philosophical debate about whether human culture, behavior, and personality are caused primarily by nature or nurture. Within the field of psychology, this so-called nature-nurture debate, is very often associated with the issue of intellectual quotient, better known as IQ. In the past psychologists have argued that the way in which a child developed was based solely on nature, genetic or hormone-based behaviors, or nurture, environment and experience. Nevertheless, this extreme way of thinking is now long outdated, and it is clear that both nature and nurture have great effect on our intellectual development. The question now lies in just how much impact each has on an
Although normal brain development can be retarded by sensory, social isolation, and deprivation, there is no sure environment that will transform a normal baby into a genius. Explain why heredity many contribute to individual differences in intelligence but not necessarily contributes to group differences. The amount of variation in a trait within a group that is attributed to genetic factors is called its heritability. For intelligence, this has been estimated at 50 percent. If we know a trait has perfect heritability, this knowledge does not enable us to rule out environmental factors in explaining differences between groups. Because of the impact of environmental factors such as education and nutrition on intelligence test performance, even if the heritability of intelligence is high within a particular group, differences in intelligence among groups may be environmentally caused. One group may, for example, thrive in an enriched environment while another of the same genetic predisposition may falter in an impoverished
Over the years, scientists have struggled to prove whether nature or nurture has the key role in the determination of key characteristics and traits that humans have expressed. One characteristic’s development that has been extremely difficult to base solely off of genetic of environmental influence is a human’s intelligence. The question of whether a person’s intelligence comes from the generations before them or does it simply develop from life experiences, lessons, and schooling. The tumultuous amounts of research and ever-changing and advancing theories all seem to agree that both nature and nurture have a partial role in the development of intelligence.
Is behavior learned? It is inborn? What of aggression, intelligence, and madness? There is a crucial relationship between the behavior of humans toward their own kind and the view of life they hold. Interest in behavioral genetics depends on wanting to know why people differ. According to Jack R. Vale, in Genes, Environment, and Behavior, recognition of the importance of hereditary influence on behavior represents one of the most dramatic changes in the social and behavioral sciences during the past two decades. A shift began toward the more balanced contemporary view that recognizes genetic as well as environmental influences on behavior. Behavioral genetics lies in its theory and methods, which consider both genetic and