Week 7 Behavioural Genetics

Question 1

What is behavioural genetics?

Answer 1

How hereditary and environmental factors combine to influence psychological characteristics

Question 2

What is heredity?

Answer 2

means the passage of characteristics from parent to offspring by way of genes

• Parents and children share 50% of genes
• Biological siblings share 50% of genes
• Identical twins share 100% of genes

Question 3

What is concordance rate?

Answer 3

Rate of co-occurrence of a characteristic among individuals (whether people are alike or not)

Question 4

What does a higher concordance rate imply?

Answer 4

Higher concordance rates among individuals who are more highly related to one another = possible genetic contribution

Question 5

What are the two types of twins?

Answer 5

Question 6

Based off twin studies, if a trait is more genetically influenced then…

Answer 6

identical twin > fraterinal twins

Question 7

Based off twin studies, if a trait is more environmentally influenced then…

Answer 7

identical twins = fraternal twins

Question 8

Is the environment for identical twins and fraternal twins really the same?

Answer 8

Identical twins are often treated the same same in an environment over fraternal twins

Question 9

What types of environments might identical twins experience?

Answer 9

• shared environment: home, family
• unique environment: friends, hobbies

Question 10

What type of study is often used to study behavioural genetics?

Answer 10

Question 11

How is behaviour expected to change depending on adoption?

Answer 11

Question 12

What type of study that goes beyond adoption studies is used to study behavioural genetics?

Answer 12

Question 13

How might behavioural genetics change when studying monozygotic twins in a study?

Answer 13

Question 14

How did a meta analysis study on monozygotic twins who were raised apart versus race together show how environment and genetics both influence behavioural genetics?

Answer 14

Allows us to tease apart the variance associated with: genetics, shared environment, & unique environment

• not a lot of difference so suggests environment does not play much of a role for identical twins
• more of a difference in fraternal twins

Question 15

What did the Minnesota Twin Study show?

Answer 15

• Genetic factors 39-58%
• Unique experience 36-56%
• Familial environment little or no

Question 16

What is a reaction range?

Answer 16

the boundaries for the expression of a genetic trait

• Environmental effects determine where person falls within these limits

Question 17

What is an example of a reaction range?

Answer 17

IQ

• Reaction range may cover 15-20 IQ points

Question 18

What are some ethical issues of twin studies?

Answer 18

Randomly assigning twins to be reared apart & deceiving participants about the goal to study twins is NOT ethical