Abstract
The paper discusses how in a normal pregnancy, a single baby develops in the uterus of the mother, but in very special circumstances, two and sometimes even more babies develop simultaneously in the mother's uterus. The paper points out that this is called a multiple pregnancy and twins are two babies in a multiple pregnancy. The paper mentions that twins are considered very special and present a fascination for science and society; in the fields of psychology and sociology, there is a special subfield called "twin studies" and they are especially important in the search for answers to the nature vs. nurture question.

From the Paper
"In a normal pregnancy, a single baby develops in the uterus of the mother. In very special circumstances, two and sometimes even more babies develop simultaneously in the mother's uterus. This is called a multiple pregnancy. Twins are two babies in a multiple pregnancy. Twins are considered very special and present a fascination for science and society. In the fields of psychology and sociology, there is a special subfield called "twin studies". Twins studies are especially important in the..."

Tags:identical, non, identical, twins

Abstract
The paper discusses the two most common types of twins; identical and non-identical twins, also known as monozygotic and dizygotic twins. The paper looks at the differences between identical and non-identical twins. The paper then talks about a third type of twins; half-identical or polar body twins.

Outline:
What Are Twins
Types of Twins
Identical Twins
Comparing Non-Identical Twins with Identical Twins
A Third Type of Twinning

From the Paper
"In a normal pregnancy, a single baby develops in the uterus of the mother. In very special circumstances, two and sometimes even more babies develop simultaneously in the mother's uterus. This is called a multiple pregnancy. Twins are two babies in a multiple pregnancy. Twins are considered very special and present a fascination for science and society. In the fields of psychology and sociology, there is a special subfield called "twin studies". Twins studies are especially important in the search for answers to the nature vs. nurture question. What is the most important factor in human development: genetics (nature) or environment (nurture)?"

Tags:multiple, births, monozygotic, dizygotic, zygotes, embryos

Abstract
Research has recently indicated that there are multiple genetic pathways leading to the development of bipolar disorder. This paper presents a detailed examination of the incidence of bipolar disorder among identical twins. The author explores bipolar disorder's genetic components and then explores whether or not identical twins have a higher incidence of the disorder than the general population.

From the Paper
"The understanding that mental illness, including bipolar disorder, is genetically based has created curiosity about where the biology is involved. One of the things that have been examined is whether or not identical twins have a higher incidence of the disorder. It is an interesting question because of the fact that identical twins have identical DNA. If a higher incidence or a correlation can be found between identical twins and bipolar disorder, it will be further evidence of the biological basis for the disorder as well as a closer look as to its biological origin being before birth, and not something that happens after birth(Taylor, 2003)."

Tags:XBP1, depression, DNA, unipolar

Abstract
One of the most fruitful methods for studying the comparative influences of nature and nurture has been to study twins. In the groundbreaking 1979 Minnesota Study of Twins Reared Apart, researches attempted to answer many of these questions. Twins, because of their identical genetic make-up, present a unique situation for viewing these sorts of results. The paper shows that this study found that genetics do play a much larger role in defining our characteristics than we might have previously suspected. It discusses the study's findings that intelligence, in particular, was affected by genes to a high degree, a fact that many found surprising.

From the Paper
"In biology, we could test which traits are the result of the "genotype" and which are the results of "phenotype" by employing such a study. It is easy to do this with physical characteristics, but what might such a study say about the way personalities develops, or other elements, such as intelligence or violent propensities?"

Tags:tabula, rasa, IQ, genotype, phenotype

Abstract
The paper shows that studying twins has been one of the most fruitful methods for comparing the differences between nature and nurture. The paper analyzes studies involving identical twins and twins separated at birth. It also examines studies involving twins that show there is a correlation between genetics and intelligence.

From the Paper
"The most famous results of the twin studies have been those involving intelligence. Generally, we tend think of intelligence as something that is not genetically inherited, but cultivated through intense study. In the Enlightenment, thinkers believed that people began life as a totally clean slate and that anything could be impressed upon them through proper education, religious indoctrination, and a solid and respectable upbringing. This concept, often referred to as tabula rasa, or "the mind before it receives the impressions gained from experience" seems soundly refuted by the Minnesota Study of Twins reared apart (Webster's II 1177). Instead of finding support for the Enlightenment notion, the study found that twins' intelligence tended to correlate very strongly despite differences in upbringing, and subsequent studies have supported this conclusion."

Tags:evidence, IQ, upbringing, education

Abstract
The paper discusses how behavior is partly a function of inherent biological factors and partly a function of external conditioning and exposure to the environment. The paper first outlines the findings of experimental observation of primates with known biological predispositions that suggests that the environment is more important than genetics. The paper then examines studies of identical human twins and deviant behavior that suggest that biology and environment are equally responsible for behavior. The paper concludes that our psychological development is likely a function of the complex interrelationship between our genetic heritage and the many influential experiences to which we are exposed during our formative developmental stages.

Outline:
Introduction
Nature
Nurture
Interplay Between Nature and Nurture
The Significance of Extreme (Deviant) Human Behavior and Identical Twin Studies
Conclusion

From the Paper
"Human beings and other so-called "higher" forms of biological life are products of their environments in many respects. Exposure to certain environmental factors and being reared under certain circumstances can influence the direction of many types of behavior. At the same time, the field of genetics demonstrates conclusively that inheritance also determines much of the development of everything from fundamental aspects of personality to the most superficial habits, likes, and dislikes."

Tags:primates, deviance, twins, traits, predispositions

Abstract
This paper explains that, although currently human cloning is banned, the presupposition is that human cloning has or will be used to produce not two identical twins but rather clones of parents that will then be biologically related to these infertile parents. Next, the author reviews the theories behind the nature argument that the cloned human have a personality more closely matched to the person from which he or she was created or the nurture argument that the clone would be a completely unique person as a result of environmental influences. The paper concludes that, regardless of the position on the nature vs. nurture debate, the ethical concerns about human cloning will remain.

From the Paper
"The bio-psychosocial perspective of the debate would indicate that like identical twins living in different times and likely different places and therefore environments the two individuals would be a lot alike in temperament and personality but would still become different people. Furthermore as it would be impossible to completely reproduce the real environment of the donor the clone would therefore logically be offered different opportunities which would result in real individuality.
"The clone's adult personality still would resemble more likely closely that of the donor but would not be an exact match of the other. The issue of temperament has a great deal to do with decisions, as when certain offerings are made to the individual infant, the individual infant will likely respond in a consistent manner according to his or her temperament. Temperament, according to Myers, is the least variable aspect of the individual, as seen by adoptive studies associated with what adoptive parent's can influence or change and what they can not.
"The adult personality of monozygotic twins clearly differs, despite the fact that they share exactly the same DNA and presumably grew up in the same household."

Tags:ban infertile bio-psychosocial, monozygotic twins, experimentation

Abstract
The paper examines studies of identical twins that research the effect of the genetic inheritance and the environment. The paper looks at how traditional psychologists have claimed that genetics is really the only effect on behavior while modern researchers show an obvious correlation between shared family environment and traits. The paper also looks at research studies that have illustrated the clear integration between the two concepts. In conclusion, the paper asserts that while genetic makeup may have much to do with one's specific personality traits, environmental factors, such as shared family settings and socio-economic conditions, is also a major effect in that respect.

From the Paper
"Personality is, without a doubt, one of the most interesting areas within the vast field of psychology. It involves the study of individual characteristics of thought patterns, emotion, and behavior, and further focuses on differences among individuals in society. As with many sub fields in the discipline of psychological studies, personality is not limited to just one basic approach, rather it deals with a wide range of different approaches such as the biological, psychoanalytical, phenomenological, and behavioral approaches (Funder, 2004). In essence, all of these areas of study compose an individual's personality in the greater social context. A specific area, one I am personally interested in, is that of behavioral genetics, which entails the various effects of genes on broad patterns of behavior, and thus personality, as opposed to the variation of environmental influences (Funder, Ozer, 2004)."

Tags:twins, traits, characteristics, abilities

Abstract
This paper explains that research demonstrates that chromosomes, the gene-carrying structures of an organism, are able to determine the level of an individual's intelligence. The author points out that scientists can measure particular inherited features by studying identical twins, who share the same genes, and can use molecular psychiatry to identify specific genes related to intelligence. The paper stresses the problem in genetic identification is that there are several forms of intelligence, such as academic intelligence, which is the traditional construct of intelligence; analytic intelligence, which is similar to academic intelligence and is suitable for testing on I.Q. tests; creative intelligence, which is, for example, a musical or artistic intelligence and cannot be accurately tested because it cannot be clearly defined; and practical intelligence, which cannot be tested because it, too, cannot be clearly defined.

Table of Contents
Introduction to Essay
General Information on Genes and Chromosomes
Information on Intelligence Tests
Positive Aspects on Intelligence Tests
Negative Aspects on Intelligence
What Can and Cannot Be Tested
Research and Experiments Conducted on Topic
Proposals from Scientists
Hypothesis from Experts
Conclusion

From the Paper
"Intelligence is the measure of a person's mental ability to function and to solve everyday problems as well as random odd problems. Individuals differ from one another in their ability to adapt to the environment, to understand complex ideas, to learn from experience and to overcome certain obstacles by taking thought. All of these concepts make up an individuals intelligence level. The most common way to measure a person's intelligence in today's society, is the IQ test. The IQ test is a series of questions involving mathematics and other types of problems that is completed by the recipients and later graded. The grade on the test determines the person's intelligence level."

Tags:chrm2, ctsd, twins, predisposition, complex

Abstract
This paper discusses the idea of immorality in cloning, since clones lack a sense of their own uniqueness. It looks at how the most glaring example of why a person that is not genetically unique can still be product of a moral agent, as shown by naturally existing genetic copies, identical twins, or triplets, etc. It explores how, although they lack a sense of their own physical uniqueness and although they are not genetically unique, they are always individual entities with unique personalities. It attempts to show that, although cloning may be immoral for other reasons, we can not draw the conclusion that a lack of uniqueness transliterates as something that is immoral.

From the Paper
"We can understand that this viewpoint of non-individualism is rationed from the idea that a human clone will not have a sense of individuality despite being a separate entity, because of the popular, yet erroneous, belief that genes determine a person's personality as well as their physical characteristics . But the clone's environmental factors will be based on his or her choices "the choices themselves being influenced by the clone's environment" while the only things being "played out" will be genetic probabilities. It is a case of nature versus nurture. According to an online encyclopaedia, www.wordiq.com, "current thinking discredits the notion that genes alone are sufficient in determining personality traits." Rather, particular genes influence the development of a trait in the context of a particular environment." For example, life choices, or the "nurture" factor, are things such as accepting a pregnancy at age 19, or learning the local language, and are different to predetermined genetic probabilities such as Huntington's disease , or brown skin."

Tags:twins, triplets, genetics