Interaction of Heredity and Environment PDF

Interaction of Heredity and Environment  Nature vs Nurture Are we born this way or do we evolve through our experiences? Plato -> Nature Aristotle -> Nurture Charles Darwin Proposed Natural Selection Evolutionary Psychology: How are we alike because of our shared biol...

Interaction of Heredity and Environment  Nature vs Nurture Are we born this way or do we evolve through our experiences? Plato -> Nature Aristotle -> Nurture Charles Darwin Proposed Natural Selection Evolutionary Psychology: How are we alike because of our shared biology and evolutionary history? Behavior Genetics: How do we differ based on our genes and different environments? E.g Are gender differences biological or societal?  Evolutionary Psychology Using Natural Selection to understand roots of behavior and mental processes What is natural selection? Natural Selection: the traits enabling an organism to survive and reproduce in a particular environment will most like be passed down  Human Genome All humans are 95% similar with 5% differences. People on opposite sides of the world can have greater genetic differences than someone from the same country Growing up in a different country than where you are from -> nature vs nurture  Behavior Genetics How are we different? Behavior genesis believe that the way our brains are set up causes us to have some behavior similarities, Examples: Return favors , conform, punish offenses, hierarchies, music, food, clothing…etc. Besides the similarity determined by our genes, how much does our environment shape our individuality? We are all also individually unique, how does our heredity work with our environment to shape us?  Where do we get our genes? 23 from each Genes parent -> 46 total Choromoes found in nucleus of the cell. Each chromosome is composed of coiled DNA (deoxyribonucleic acid) Genes are small segments on that DNA molecule Have ~ 20,000 genes but not all are active Which ones are expressed can create our differences When turned on, the genes provide a code for our bodies creating protein  Summary Humans are more similar than they are different, actually only 0.6 difference in our genomes than that of chimpanzees. Evolutionary psychologist and behavioral geneticist look at the similarities and differences between us and whether heredity or environment plays a greater role in our individuality  Twin Studies Twins are as close as we can get to identical genomes. The genes and the expression of the genes are almost the exactly the same. Important rule when comparing nature vs nurture, because the nature is controlled There are alot of ethical concerns with studies done on twins. E.g the three identical strangers study The study separates twins and triplets and put them in separate homes, their adoptive parents did not know their children were part of an experiment. The experiment resulted in severe emotional damage all around. Physicians, social workers, adoption agents all stayed silent for 20 years despite seeing the damage they were causing. Identical vs Fraternal Twins Identical Twins (monozygotic) Developed from a single fertilized egg that splits, they are genetically identical. Twins have the same genes but not always the same number of copies, can make them more vulnerable for disorders. Identical twins usually share a placenta, sometimes can lead to better nourishment of one or the other Fraternal Twins Developed from two separate fertilized eggs. Genetically different, same as siblings. Being fraternal twins increases risk of one also being diagnosed with a disorder the first has.  Some genetic traits are going to develop the same Gene - way regardless of any environment e.g eye color Other traits are only turned on in certain Environment environments What we want to look at is how the environment Interaction and the genes interact The impact of these studies can save lives, e.g who is more at risk of covid  Epigenetics Epigenetics the study of the molecular mechanisms by which environments can influence genetic information Genes are self-regulating (can regulate their own expression ) E.g An African butterfly green in the summer and brown in the fall-winter controlled by the same gene E.g blisters after the gym The epigenetics of a gene can be affected by diet, stree, drugs..etc. A study run on rats showed that mothers lick their infants. When the infants are not licked there was a genetic “on” switch that wasn't activated leading to disorders. It is thought that childhood trauma , poverty, malnutrition can affect the expression of certain genes  Review Evolutionary psychologists seek to understand how our traits and behavior tendencies are shaped by natural selection. Genetic variations that increase the odds of reproducing and surviving in a particular environment are most likely to be passed onto future generations. Some genetic variations arise from mutations, others from new gene combinations forged at conception. Humans share a genetic legacy and are predisposed to behave in ways that promoted our ancestors’ surviving and reproducing. Charles Darwin’s theory of evolution is one of biology’s fundamental organizing principles. He anticipated today’s application of evolutionary principles in psychology. Behavior geneticists study the relative power and limits of genetic and environmental influences on behavior. Most of our differing traits are polygenetic, and are influenced by the interaction of our individual environments with these genetic predispositions.  Review Studies of identical (monozygotic) twins versus fraternal (dizygotic) twins, separated twins, and biological versus adoptive relatives allow researchers to consider the effects of shared environment and shared genes, which sheds light on how nature and nurture influence our traits. Shared family environments have little effect on personality, although parenting does influence other factors. Our genetic predispositions and our surrounding environments interact. Environments can trigger genetic expression, and genetically influenced traits can influence the experiences we seek and the responses we evoke from others. The field of epigenetics studies the molecular mechanisms by which environments can trigger or block genetic expression.