Nature Vs. Nurture

For more than a century after Galton’s observation, twin studies have become an essential tool when studying behavioural genetics. It allows researchers to understand how genetics and the environment play a role in an individual’s development which include biological, behavioural and psychological disorders. Thus twin study is used to evaluate the degree of genetic relatedness and is commonly used to explore the influence of environment and genes when studying patterns of aggression, intelligence, schizophrenia, and even alcohol dependence.

The Minnesota twin study, Bouchard et al. (1990) was a longitudinal and cross cultural study to check the effect of heredity and environment on intelligence. This study was conducted on monozygotic and dizygotic twins separated from each other in infancy and reared apart. Approximately 50 hours of interviews and testing was done on each twin. For measuring intelligence, the WAIS test and the Raven test was used. The correlated IQ rates of the monozygotic twins reared apart were then compared to those that were reared together and dizygotic twins raised together to understand the result of heredity and environment on intelligence. This was useful as they shared similar genetic makeup but were exposed to different environmental conditions. Monozygotic

Studies have shown that identical twins have similar behaviour and task performance (Delvin, 2015), and this is often attributed to having identical DNA. However, it is often overlooked that they were brought up in the same home, by the same caretakers? Although we might have a gene for a certain trait such as intelligence for example, if we are nurtured in an environment that encourages hard work and positivity, good academic performance can also be achieved (James, 2008). All these are but a drop in the ocean of the examples of physical traits that are contributed by both nature and

Twin studies are part of the methods used in behavior genetics, which includes all data that are genetically informative – siblings, adoptees, pedigree data etc. Monozygotic (identical) have all of the same genes and dizygotic (fraternal) have 50% of the same genes. Twin studies are very unique.

Researching genes has been aided by the increase of technology in recent years (Bishop, 2009). Using twin studies, researchers are better able to determine whether a disorder is genetically or environmentally related since monozygotic, or identical, twins share nearly the same genetic makeup (Bishop, 2009). Bishop (2009) explained that Specific Language Impairment (SLI) was previously thought to be caused by environmental factors before twin studies found genetic links. Using linkage analysis, or searching for mutant DNA, researchers can discover what the specific genetic links may

This article has a huge impact in the study of behavioral genetics. It shows validity in the nurture side of the nature-nurture debate. It shows that most of the external similarities in twins is due to genetic influences. There are some invalid points to the study, including how environment influences symptoms of CD, ODD, and hyperactivity. But overall the study was pretty valid and true, giving an interesting perspective to the behavioral genetics

The Minnesota Twin Study is a correlational study which seeks to establish the relationship between genetics and/or environment on personality. The study uses twins as a basis due to shared genetic material. The two types of twins, who were separated at birth and raised in different environments, are the (adult) participants; the data accumulated from these twins was compared to the control

Twin studies are vital for behavioral genetics in the sense that researchers can study how genetics can influence certain traits. For example, identical twins many be raised in the same household and both enjoy horseback riding, while a set of fraternal twins may not both enjoy horseback riding. The standard study conducted is based on twins raised in the same family environment, as this method can show how life experiences play a role. Many twins are raised in the same home and share a lot of the same experiences, which can impact their behavior, no matter the genetic makeup. A significant theory associated with twin studies is the Random Mating theory. In this theory, researchers tend to assume that people are as likely to choose partners who are different from themselves as they are to choose partners who are similar for a particular trait (2017). While twin studies are essential in gathering data for behavioral genetics, they can only estimate the heritability of a trait, while molecular genetics attempts to pinpoint the effects of a particular gene.

Twin studies help uncover the level of importance of both genetic and environmental influences on an individual. These studies are usually done with siblings and focus on what things have an impact on their

When studying twins, researchers mainly study identical twins because they strive to see the influence of nature and nurture on the traits of these identical twins. One way of doing this is by splitting the twins up at birth. Obviously, the twins are going to share genotypes and so they are going to has similar influences of nature, but researcher aim to see if interests, habits, and skills are influenced more by nature or nurture. By splitting the identical twins up, it is easier to see which trait is influenced by either nature or

There are many different variables one can look at in order to answer the question of how identical are the identical twins. In this study intelligence is selected as a variable to be analyzed. The study explores the impact of environment, genetics and sex on intelligence. What influences intelligence has been studied as part of health and development for a long period of time? This study provides with data on genetic factor and environment effect on development. Also it will help us understand how identical twins can or cannot be different regardless of their similar genetic makeup.

The median correlation of identical twins growing up together was 0.52 and it was closely followed by median correlation of identical twins reared apart, which scored 0.49. This means that variable of being a twin and being similar was positively correlated in both cases although twins reared apart live in different environment. Results suggest that shared environment doesn’t really account for the differences in twins. Furthermore results of

In this way, twin studies give psychologists greater insight into the role of genes in intelligence. Critics of twin studies suggest that twin similarities may be a result of chance rather than evidence of heredity at work. Also, because adopted twin children tend to be placed in similar settings, critics suggest that the trait similarities may be a matter of comparable experience rather than one of heredity.

A number of recent twin studies have shown that our genes, to a surprising extent, influence behavior. Even matters that naturally seem to be a reflection of one’s personal experiences, such as political stance or religious views, have been proven by various studies to be largely controlled by genetics (Times Higher Education, 1997). Researchers at the University of Minnesota launched the Minnesota Twin Family Study in 1979, in which over a period of 20 years, they studied 137 pairs of twins – 81 of which were identical. Through this study, researchers found that about 70% of IQ variation across the twin population was due to genetic differences among people (LiveScience, 2014); a more recent study in 2009 also supported this. Behavioural

Who were the participants in the study? The participants in this study were two birth cohorts (1994 &1995) of same-sex twins and their parents from Wales and England. 56% were monozygotic and 44% were dizygotic twin pairs. The participants were members of the Environmental Risk Longitudinal Twin Study to study how genetic and environmental factor’s can shape a child’s development and specifically how a father’s role in his child’s life, (whether living with or away from the child and whether he is very antisocial or just a little) can affect the child’s own behavior and conduct. Out of 15,906 pairs of twins born, 71% joined the study. The children were all around the age of five as data was collected within 120 days of the twin’s fifth birthday. Several of the 1,210 families that were used in this study had to be excluded out of the findings due to them moving or them not being able to speak English.