Study Guides (238,613)
Canada (115,253)
Psychology (1,612)

MIDTERM PART 4, psychology 1000, 2013.docx

9 Pages
Unlock Document

Western University
Psychology 1000
John Campbell

Genetic influences -It is known as nature and nurture together. Scientists realized that asking whether a particular behaviour is caused by genetic or environmental factors makes no sense. Chromosomes and genes  Gregor mendels research on garden peas was the beginning of the genetic theory  He found that heredity involves the passing of specific organic factors that might produce visible characteristics in the offspring or they might simply be carried for possible transmission to another generation  Genotype o Specific makeup of an individual  Phenotype o The observable characteristics produced by the genetic endowment  **note genotypes are present from conception and never change; but phenotypes can be affected by other genes or by the environment**  The egg and sperm carry heredity information in the form of chromosomes o Tightly coiled molecule of DNA that is partly covered in protein  The DNA portion of the chromosome carries the hereditary blueprint units called genes  Humans have 46 chromosomes in every cell except sperm/egg (has 23)  At conception 23 from sperm and 23 from egg combine and produce a zygote (46)  Alternative forms of a gene that produce different characteristics are called alleles  Genes code for proteins and proteins make up structure and chemical reactions within cells sustaining life of the cells Genetic based disease called FFI  Fatal familial insomnia  Died in 1765  In the first stages we recognize the first stages of insomnia  Within a month it is clear that you have a different disease then just insomnia  They are forever trying to fall asleep  They eventually go into a coma and then die Recap  Genetic disease around the age of 50 where the person cannot sleep and eventually die  There is no cure  Sleeping pills just make it worse and cause comas  Is it dominant recessive?  Is regular insomnia genetically related? Dominant/ recessive effects  Genotype and phenotype are different because some genes are dominant and some recessive  Dominant o That gene will be displayed in the phenotype  Recessive o That gene will not be displayed in the phenotype but will be in the genotype  Polygenic transmission o A number of gene pairs combine their influences to create a single phenotypic trait Mapping the genetic code  In 2001 the human genome was completely mapped out  They discovered humans have fewer genes than expected (25, 00 compared to 100,000) Genetic Engineering  Recombinant DNA procedures o Using certain enzymes to cut the molecules of DNA, they can combine them with DNA from another organism and insert it into a host where it will grow  Recombinant DNA was used to create HGH o HGH made it possible to treat 121 children with abnormally short stature who were deficient in the hormone o The positive social and psychological aspects of using HGH treatments has been a large interest to psychologists  Molecular biologist have developed methods for inserting new genetic material into viruses that can infiltrate neurons and modify their genetic structure o This can be used to study genetic influences on behaviour such as learning, memory, emotion and motivation  Gene knockout o When a specific gene is altered in a way that it prevents it from carrying out normal function o Using gene knockout we can look at the effects on behaviour  Determine the importance of certain neurotransmitters o Holmes, Murphy and Crawly  Used mice with a knockout for the mechanism in the reuptake of the neurotransmitter serotonin  These mice showed increase in anxiety and stress responses much like a human o Setbacks are: knocking out a single gene may disrupt the function of other genes o Gene knockout can be used to help out with Schizophrenia Behaviour Genetics Techniques  Knowledge of genetic transmission tells us how genetically similar people are depending on their degree of relatedness o Parent to child probability of sharing the same genes is %50 o Siblings probability of sharing is also %50 o Child and grandparent is %25 o Half-siblings is %25  Behaviour genetics are interested in studying how environmental factors combine to influence psychological factors  Heritability coefficient o An estimation of the extent to which variation in a particular characteristic within a group can be attributed to genetic factors o **NOTE: heritability refers to differences in the trait across individuals not to the trait itself*** o *Heredity-passage of characteristics from parents to offspring by way of genes** DIFFERENT!!!!!!!  Heritability applies only to differences within a group, not to differences between groups**  Concordance o Means when a characteristic has higher co-occurrence in people who are more highly related to one another, then this points to a possible genetic contribution, particularly if the people have lived in different environments  Adoption Study o A person who was adopted early in life is compared on some characteristics with the biological parents and the adoptive parents o If the person is more similar to the biological parents then to the adoptive parents then genetic influence is suggested  A study on schizophrenia showed that the biological family members of an adoptive child with schizophrenia were 12% more likely to also have the disorder compared to only 3% of the adoptive family members  This indicated a hereditary link  Twin Studies o Monozygotic twins (identical) come from the same fertilized egg o Dizygotic twins (fraternal) come from two fertilized eggs o The studies have shown that identical twins are much more similar then fraternal twins indicating a genetic heritability  Behavioural geneticists have been led to the conclusion by these studies that psychological characteristics have a notable genetic contribution o A study done showed the differences between fraternal twins reared together, identical twins reared and not reared together o The results concluded that identical twins are still more similar than fraternal twins even when not reared in the same homes  Researches also wanted to test if environmental factors interact with genetic endowment in important ways o They found that an adoptive child had a greater chance of being a criminal if his biological father was a criminal even though his adoptive father was not o The child was less likely to have a criminal behaviour if the biological dad did not and the adoptive dad did o BUT, when both dads were criminals then the child had the highest likelihood of being one as well  This study showed that genetic and environmental factors almost always interact with each other to influence behaviour Genetic influences of behaviour Heredity and environment  To what extent are differences in intelligence due to genetic factors and to what extent does environment determine differences in intelligence?  A large study done showed that genes play a significant role in intelligence but not all  The environment also contributes significantly ranging from 30- 50% of peoples IQ variation Biological reaction range  Reaction range o For a genetically influenced trait in the range of possibilities –the upper and lower limits- that the genetic code allows  This does not mean for example that intelligence is fixed at birth, it just means there is a range of potential  This is where environmental effects come in because they determine where a person falls within that range  Typically a person can have a high range but if they were not raised in the right environment then they will fall towards the lower end of their range  **exception: someone who has a high range and was born in an enriched home may still fall towards the lower end of the range because that person was uninterested and did not apply themselves** o This indicates that there are other characteristics that influence intelligence Genes- Intelligence  Denial tammet: o He is a genius o He can relay off 22,500 numbers of pie’s decimal places o When he is doing calculations in his head, numbers and colors come to him o He says that he can see the numbers as a picture that he memorizes  Chris Langan o He still works in a bar even though he is the smartest man in the world o His IQ is 190-210 o Buckle was his first word o He developed very rapidly o At the age of 3 or 4 he started to write a book o He knew he would do something that would qualify him as a genius o He was picked on for being smart and small as a child o He says his step father was a psychopath and would beat him for being smart  Differences and similarities o Daniel was strong in languages and numbers and Chris said that language was easy for him and numbers was a little bit more challenging than him o Daniel was more about memorizing where Chris was about intuition o Chris seems to be very good at things that we do all the time where Daniel does things that have never been done before o Chris doesn’t show how smart he is as he still works in his bar, Chris is more social o Daniel was a little bit more socially awkward o From a very early age they both knew they were very smart o Daniel suffered from seizures and then afterwards he could do all of these calculations Behaviour genetics and personality  Hans Eysenck suggested that there was a biological basis for major personality traits  Since Hans there has been evidence for specific genetic components of some personality traits  Example neuroticism and gene allele hat increases the action of serotonin  One theory of personality traits is called Five Factor Model 1. Extraversion-introversion 2. Agreeableness 3. Conscientiousness 4. Neuroticism 5. Openness to experience  This showed that 40-50% of personality variations are attributable to genotype differences  Twin studies were again done to see if personality traits were related to genotypes  They found that identical twins are far more similar in personality traits than are fraternal twins  Also it makes little difference whether they were reared together or in different adoptive homes  *JIM TWINS**  Genetic influences have been reported for a tendency to abuse alcohol, a variety of personality disorders, seasonal mood changes and anxiety  NOTE: it shoul
More Less

Related notes for Psychology 1000

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.