2.01 Interaction of Heredity and Environment
2.1 Interaction of Heredity and Environment
Basics of Biology
-Environment is every external influence that exists. Ex: religion, politics, culture, morals, etc.
-Everyone has 46 chromosomes (23 pairs) in each cell. Our chromosomes are structures made up of DNA, and DNA containing genes
-There are both expressed /active genes and inactive genes, depends on your environment
- A genome is all of the genes that make up an organism
Nature vs. Nurture debate
A big question in psychology is the nature vs. nurture debate. The question being, are we being more influenced by our genes and heredity or by our experiences. Biological psychologist are interested in studying the links or connections between our biological (neurons, DNA, etc.) process and our psychological processes.
Twin and adoption studies: One of the ways psychologists study the debate. If they can study identical twins separated at birth, they will compare and contrast them. They will look for similarities and differences in their abilities, traits, characteristics and this can give insight into whats more influential in the debate
-Identical (monozygotic) twins: Developed from the same fertilized egg the splits into 2. Each twin has the same genes, but not the same amount of copies of those genes. This explains small difference between twins
Ex: A study by Thomas Bounchard, he found that the IQ of twins living separated at birth had a correlation of 0.69 while the IQ of twins living together had a correlation of 0.88. The scores found that environment had some effect on IQ scores, but it is still heavily influenced by genetics. The study also showed twins separated at birth had similar physical characteristics, that is called effective psychological environment.
- Fratenial (dizygotic) Twins: Develop from a different fertilized egg
Heritability: tells how much of variation exists between individuals is due to genetics. NOT the amount of a trait is inherited. Can be used to understand the variation that exist between individuals that are studied.
Types of geneticist
Behavioristic geneticist: Interested in studying the power and limits of genetic and environmental influences on your behaviors Ex: mutations, DNA, chromosome pairs
Molecular geneticist: Study the molecular structure and functions of genes and how they play a role on out behavior. How genes give us traits like body weight, sexual orientation, etc.
Epigeneticist: Look at how the environment influences how our genes express themselves without an actual change in DNA. Environmental changes explain why each child in a family is different, despite their same genetic background.
-Genetics give you a foundation of who you are but the environment shapes you into the person you are.
Evolutionary: Focus on the principle of natural selection to explain our behavior and the mind. This states that we are more likely to inherit and pass on traits that have been important to human survival