Influence of heredity and hormones

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As you explore the link between genes and human behavior, please note that the topic is both highly controversial and vast. However, I give you some notes, links, and ideas to get started. After writing your draft, please send to us a new posting bid and we will edit and offer feedback. Thank you so much!

As you compare the relationships between genes and various human behaviors, you might acknowledge that a strong bond prevails. Psychologists use measures such as "strain studies help to determine the heritability of certain traits in inbred animals; selection studies estimate the heritability of a trait by breeding animals with other animals that have the same trait" (http://cwx.prenhall.com/bookbind/pubbooks/morris5/chapter2/custom1/deluxe-content.html#M). In other words, these studies, especially family and twin data show that genetic influences upon human behavior are quite strong. Researchers also use adoption studies to examine the influence of heredity and environment on human behavior.

When you look specifically at behavioral influences, heredity plays a major role. One example is from the average risks study for schizophrenia among biological relatives of people who exhibit this disorder. Please refer to the chart at http://cwx.prenhall.com/bookbind/pubbooks/morris5/chapter2/custom1/deluxe-content.html#M. This study shows that that identical twins have a 49% lifetime risk compared to only 1% of the general population. Thus, this study demonstrates the strong role of heredity upon human behaviors. Therefore, twin studies offer critical evidence when looking at the role of heredity within human behavior. "Because humans cannot be bred for certain traits and are hard to manipulate in an experimental fashion" (http://www.sparknotes.com/biology/animalbehavior/instinct/section4.rhtml, twins are critical in this field.

Besides this study, you might also argue that behavioral genetics research also locates "specific genes and alleles responsible for some behaviors" (http://www.sparknotes.com/biology/animalbehavior/instinct/section4.rhtml). Although it is apparent that both nature and nurture work together in determining a behavior, it is ...