Twins provide a valuable source of information for health and psychological research, as their unique relationship allows researchers to pull apart and examine genetic and environmental influences. ... Twin studies allow researchers to examine the overall role of genes in the development of a trait or disorder.
Why are studies of identical twins raised in different environments extremely valuable in understanding the genetic causes of a multifactorial disease?
We study twins to understand how much of the difference in a trait between people is caused by genes and how much is caused by the environment. These studies are important because they help scientists quantify genetic and modifiable environmental factors that increase the risk of certain diseases .
Why are studies of identical twins raised in different environments extremely valuable?
Why are studies of identical twins raised in different environments extremely valuable in understanding the causes of a disease? They are extremely valuable in understanding the causes of a disease, because it differentiates between nature vs. nurture.
Why are identical twins useful for studying environmental variation?
Twins are a valuable source for observation because they allow the study of environmental influence and varying genetic makeup : “identical” or monozygotic (MZ) twins share essentially 100% of their genes, which means that most differences between the twins (such as height, susceptibility to boredom, intelligence, ...
Why is it important to study twins that were raised separately?
Twins reared apart help identify genetic and environmental influences on behavioral development (Segal, 2012). Monozygotic twins reared apart (MZA) allow direct estimates of genetic effects on behavior and health, because they share all their genes, but differ in their environments.
What are the limitations of twin studies?
Limitations of twin studies
Results from twin studies cannot be directly generalized to the general population , due to lack of randomization; in addition, they are different with regard to their developmental environment, as two fetuses growing simultaneously.
What do twin studies tell us about intelligence?
Genes have a very strong influence over how certain parts of our brains develop , scientists in the US and Finland have found. In identical twins, these areas showed a 95 to 100 per cent correlation between one twin and the other – they were essentially the same. ...
Do identical twins raised apart have similar personalities?
Comparing twins raised separately with those raised in the same home allows researchers to determine the relative importance of heredity and of environment in their development. Although some twins go out of their way to emphasize differences between them, in general identical twins are very much alike in personality .
Why are twin studies unethical?
The study, which has since been criticized for being unethical — for example, neither the children's biological parents nor the adopting families were informed — was an attempt to get at the central psychological questions of “nature versus nurture” and the “twinning reaction.”
Do twins have the same IQ?
It was concluded, among many other things, that identical twins are about 85 percent similar for IQ , whereas fraternal twins are about 60 percent similar.
Do twins have the same fingerprints?
Even identical twins – who have the same DNA sequence and tend to share a very similar appearance – have slightly different fingerprints . That's because fingerprints are influenced by both genetic and environmental factors during development in the womb. ... But fingerprints are not unique to humans.
How can identical twins look different?
Even if 2 people have the same set of genes, because of the different environments they experience – i.e. in the womb (maybe one got more nutrients than the other), the types of illnesses they have had as they grew up; the lifestyle they lead, etc, there can be differences in how much each twins' genes are turned on or ...
What is the heritability of identical twins?
As a matter of fact, identical twins have a heritability of 0 , since any variation in their behavior cannot be accounted for by genetic differences.
What are the two conclusions of Bouchard's study?
The research team found that identical twins who are reared apart had the same chance of being similar as twins who were raised together . Bouchard and his colleagues concluded that genetic factors have a large influence on behavioral habits demonstrating the influence of the genetics on development.
What makes an egg split into twins?
To form identical or monozygotic twins, one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information. To form fraternal or dizygotic twins, two eggs (ova) are fertilised by two sperm and produce two genetically unique children.
Why do identical twins who grew in different countries do not look the same?
Yes! Identical twins came from the same sperm and egg, so they have the same chromosomes and genes. ... As identical twins get older they may look more and more different, because they are exposed to more diverse environments . The science of epigenetics explains how these environmental influences can affect the genes.
