Module 1.1: Interaction of Heredity & Environment Flashcards
What is another word for heredity?
Nature
What does heredity refer to?
Heredity refers to genetic or predisposed characteristics that influence physical, behavioral, and mental traits and processes
What is another word for environmental factors?
Nurture
What do environmental factors refer to?
They refer to the external factors that one experiences, such as family interactions or education
What is the conclusion that the nature vs nurture debate has reached today?
Today, it is believed that all traits and skills are the result of the interaction between heredity and environmental factors.
What is the genome?
It is the set of complete instructions that make a human, containing all their genes
Where is the genome found?
It is found in the nucleus of the human cell
How many chromosomes are found in the human nucleus?
46 total - 23 from each parent
Why is a child’s sex determined by their father?
Because the male carries both an X and Y chromosome, while the female carries 2 X chromosomes.
Where are genes located?
Chromosomes in the nucleus are made up of DNA, and segments of DNA consist of genes
Why are genes important?
They consist of instructions for making proteins that determine our traits
Are all our genes always activated?
No; some genes are always “on” while others are triggered by factors in the environment
What do evolutionary psychologists believe about trait inheritance?
They believe organisms inherit genes that help them survive and increase their chances of spreading their genes through reproduction
What motives are believed to underlie all behavior?
Survival and reproduction
What did Charles Darwin theorize?
That organisms inherit traits from their ancestors’ genes
What are mutations and why are they important?
Mutations are random mistakes in gene replication, and they are important because they may help organisms adapt to a particular setting
What is natural selection?
The likelihood that organisms’ adaptive genes are passed to their offspring, due to a longer life span and increased reproduction
What is evolution?
When the genome of a population is altered, causing mental and behavioral changes for members of the group
What was Galton the first to do?
Try to objectively study intelligence
What did Galton believe about intelligence?
He believed it was innate (inborn) and coined the term “eugenics”
What is the meaning of eugenics?
The belief that “superior” individuals should procreate to genetically “improve” the human species
What did Galton believe about intelligence and immigrants?
He believed intelligence test scores identified genetically “inferior” immigrants. He argued immigrants should be kept out of England and/or sterilized
What happened as a result of eugenics spreading globally in the 1920s?
Thousands of women were sterilized without their consent in the US until the 1970s, and Asian immigration was banned.
What does behavior genetics study?
It studies human differences, seeking genetic and environmental causes
Who does behavior genetics study?
- Monozygotic, genetically identical twins raised together OR raised apart
- dizygotic, fraternal twins
- adopted children from different biological parents
What is the difference between monozygotic and dizygotic?
Monozygotic means “identical” twins from 1 egg, while dizygotic means “fraternal” twins from 2 separate eggs.
What is the difference between identical and fraternal twins?
Fraternal twins share 50% of their genes; they are NOT genetically more similar than any other siblings
What did behavior genetics research find?
- Identical twins are more likely to share personality traits (even when raised apart) than fraternal twins or siblings in an adoptive family with different parents
- Adopted children who are environmental (not genetic) relatives tend to share the same political views, values, manners, attitudes, education, and religious faith
Why do psychologists use twins to study the genetic causes of human behavior?
If monozygotic twin sets share more similarity in a trait than dizygotic twins, the trait has a genetic component
Why do psychologists study adopted children to study genetics?
Children and their adoptive parents tend to have similar attitudes, values, manners, and political and religious beliefs - all of which are unrelated to heredity. Therefore, parenting (environmental factor) does matter
How do nature and nurture interact?
Genetic traits trigger responses from the environment that can affect gene activity
What is diathesis?
A genetic predisposition
How can diathesis and environment interact?
A genetic predisposition for a child’s hyperactivity may evoke an angry response from parents, triggering the child’s genes to release less of a neurotransmitter such as serotonin
What is epigenetics?
The study of environmental influences on gene expression occurring without DNA change - how an individual’s lifestyle, environment, choices, etc. can directly interact with the genome
What are epigenetic marks?
They are chemical modifications that occur on the DNA or on proteins associated with DNA - do NOT alter the genetic code itself, but influence how genes are turned on or off
How early on can life experiences lay down epigenetic marks?
As early as the womb
What are methyl groups?
organic molecules containing carbon and hydrogen
What is DNA methylation?
is the addition of methyl groups to the DNA - a common type of epigenetic mark
