Many twin studies have also shown results that genetically identical twins (MZ) have a greater number of inheriting depression than non-identical twins (DZ). For instance an experiment carried out by Prince in 1968 expected that MZ twins would have a higher concordance for depression compared to DZ twins. Results found were that the MZ twins who were raised in the same environment/family showed a concordance of 68% and DZ twins had a lower concordance of 28% for bipolar disorder only. This is evidenc...
In a study done on the genetic and environmental factors influencing the emergence of these traits it was shown that both of these play large factors. The researchers studied one hundred and twenty-three pairs of identical twins and one hundred and twenty-seven pairs of fraternal
Many conducted research by looking into identical twins and their personality types. Even when the twins were separated, they expressed some of the same behaviors and traits as their twin which concluded that some traits are inheritable. This thought can go deeper into the brain through a domain called personality neuroscience where people have discovered the dopamine receptor gene (Pastorino & Doyle-Portillo, pg. 479, 2015). This gene influences the amount of serotonin in the brain and can cause greater anxiety levels in these people. The founding of this gene solidifies the fact that biology and personality are indeed
Fate, F. (2013, January 16). Identical twins: The truth behind their similarity. The Frozen Fate Reproductive Medicine Ethics. Retrieved November 16, 2013, from http://thefrozenfate.wordpress.com/2013/01/16/identical-twins-the-truth-behind-their-similarity/
...reversals that question the validity of that assumption. She believes that it is more important to recognize the fact that twins and other multiplies try to find ways to distinguish themselves from each other (p. 124).
Identical, conjoined, and half-twins are all examples of intrinsic variability in humans. Intrinsic variability exists in all animals and is an adaptive mechanism built into the nervous system in response to input. This mechanism allows humans to distinguish the same inputs as different from one another and therefore, the possible outputs vary with time. It is possible that due to identical genetic input, the twins could share identical neural pathways and identical I-Functions. This hypothesis could explain the identical behaviors and inter-connectedness of feelings and thoughts that twins share. Differences that are seen in twin behaviors could simply be due to intrinsic variability causing differing output or behaviors.
How adoption and twin studies have influenced the “nature verses nurture debate” has been a focal point for many researchers and people around the world which has caused controversy and many views regarding the topic. “Twin studies look into behaviour in identical and none identical twins and adoption studies separate the effect of nature from nurture, or at least do more successfully than twin studies.” ("The Usefullness of Twin Studies and Adoption Studies | psuea7", 2011, p.1) These studies are used to provide plenty of strong and reliable evidence that and positively influence the Nature vs. Nurture debate. “The Nature vs. Nurture debate is the scientific, cultural, and philosophical debate about whether human culture, behaviour, and personality are caused primarily by nature or nurture. Nature is often defined in this debate as genetic or hormone-based behaviours, while nurture is most commonly defined as environment and experience.” (("Nature vs. Nurture", 2014, p.1) Many controversial debates have surrounded this issue and many researchers are trying to find evidence to justify if twin and adoption studies have an effect on the nature vs. nurture debate. Twin and adoption studies have had a positive influence on the nature-nurture debate because research and evidence has identified different issues and quality information to help the nature-nurture debate evolve. This essay will outline these positive influences and will elaborate on the research and evidence that has helped the nature-nurture debate. The three influences of twin and adoption studies that will be discussed are the influence of researching the affects of behavioural issues such as schizophrenia, the influence of undergoing research on the drinking affects an...
Many twin studies offer support for the genetic approach and although correlation study findings have varied, what remains constant across all studies is a greater association of aggressiveness with MZ than Dz twins, whether reared together or apart, strongly indicating a genetic contribution. McGuffin et al found MZ twins aggression levels correlated more highly at 0.87 than DZ twins at 0.72, O’Connor 1980 found a correlation of 0.72 between MZ twins whereas canter found a weak correlation of 0.14 thus suggesting other factors played a bigger role.
I remember that at an early age that I was never alone, whether the reminder comes from family or strangers, I have always had a constant reminder that helped me to feel safe in the world, but in other people’s eyes, I am not an individual but I am only a half of a whole. When I was little there was a time when I didn’t know that being a twin, an identical twin at that, would hinder my growth as an individual. According to Burke, when asked what makes you unique her reply was “I don’t know”, followed with “because I have a twin.” When asked to elaborate as to why she doesn’t know, her response was “we’re compared and seen as the same person even though in some ways i’m different from her, like the fact that I was born with my own brain and
Collins, Nick. "It's nature, not nurture: Personality lies in genes, twins study shows." The Telegraph. 16 May 2012. Telegraph Media Group. 05 Feb. 2014 .
On October 9, 1968, a set of twins were born, but separated at birth and ultimately, put up for adoption. The decision to separate the twins came from the adoption agency who wanted to conduct a nature versus nurture experiment; however, the experiment was conducted in secret. However, for unknown reasons, the experiment never developed to fruition. Unaware the child they adopted was a twin; both sets of parents raised a singular child. Thirty-five years later, one twin began a search for her biological mother through the adoption agency, only to find out that she was born a twin. Upon learning her identity, she reached out to her twin and they began the journey of getting to know one another by comparing characteristics that appeared similar such as temperament and mannerism. They even discovered that they both held positions as a film critic and enjoyed almost identical movies.
Although inherited conditions have been linked to childhood obesity, they are rare. However it has been noted that children with obese or overweight parents are more than likely to be obese themselves, the reason for this as described by Heaton-Harris (2007) is because of the length of time it takes to break a bad habit. Unless the parents are correctly informed of healthy diets themselves the problem will continue from an ill-informed childhood into adult hood. Other probable causes are numerous ones. Fast food and processed foods becoming more read...
The nature- nurture debate has many different case studies, which often questions environmental and hereditary aspects of the nature- nurture debate. A tangent which is focused on in this essay is how the case studies of schizophrenia and IQ, specifically affect twin and adoption studies. This essay will firstly, give a brief outline of the nature-nurture debate and the definitions of twin and adoption studies. Secondly, it will illustrate two main case studies, which are IQ and Schizophrenia studies. Thirdly, will contrast and compare the two and research’s impact on the case studies in regards to nature vs. nurture and finally, will conclude with the impact of the nature-nurture debate and twin and adoption studies.
Segal, Nancy L. Entwined Lives: Twins and What They Tell Us about Human Behavior. New York: Dutton, 1999. Print.
I have always been fascinated by conjoined twins and have always had questions about them like; what do the Siamese have to do with conjoined twins? Why does this form of twin happen? What, if any genes cause this? What types of Conjoined twins are there? How does the environment affect, if at all, the biological families' gene pool? In my research in efforts to prepare this paper, I found the answers to this question and many more. This term paper will cover the types of conjoined twins, the biological occurrence that causes conjoined twins, a look into some of the genetic and environmental causes of conjoined twins, the types of conjoined twins and the genetic and social impact of conjoined twins.