Chapter 3 Smore

By: Joey Gugliotta and Michael Portera

Twin Studies

Identical twins they are genetically identical and form, they develop through a single fertilized egg that splits into two. Fraternal twins develop from separate eggs, they are not any different from regular brothers or sisters. Unlike regular brothers or sisters fraternal and identical twins have a higher risk of disease if their twin has one. Identical twins are genetically identical, but they share many behavioral similarities also. For example, if one identical twin gets divorced the chance of the other twin getting divorced goes up 5.5 times.
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Adoption Studies

An adoptee has two groups of relatives; his or her genetic relatives and environmental relatives. Adoptees' bear the traits of their biological parents more so than their care giving adoptive parents. A finding from studies show that people that are raised together don't much resemble one another in personality. Children in adoptive homes are no more likely to share the same personality traits then to share them with the kid down the street. Although adoptive parents don't have an impact on personality traits, they do however have an impact on a children's attitude, faith, and politics.
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Natural Selection

Natural Selection is a gradual process by which biological traits become either more or less common in a population due to environmental changes or needs. Biologists use natural selection to explain the mating behaviors and habits of many species. Whereas evolutionary psychologists use it to explain the sex patterns and differences between men and women.

Molecular Genetics

The molecular genetics quest is the new frontier of behavior- genetics. Psychologist Robert Plomin said "the DNA train is leaving the station" and every psychologist is climbing aboard. Most human traits are influenced by teams of genes. Genetics tests can now reveal populations that are at risk of at least a dozen diseases. Geneticists and psychologists are teaming up to find and pinpoint genes that put people at risk for genetically influenced diseases.
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Heritability is the extents to which variation among individuals can be attributed to their differing genes. Behavior geneticists can use the twin and adoption methods to mathematically estimate the heritability of a trait. We can attribute to genetic influence 50 percent of the observed variation among people.