PSY 101 1st Edition Lecture 5 Outline of Last Lecture I. Central nervous systemOutline of Current Lecture II. Behavioral geneticsIII. Evolutionary psychologyCurrent Lecture-Reach ch 4 (section on gender will not be on exam)-Read ch 3 section on dual process models (at beginning)-How do genes work?-Every cell that contains a nucleus contains the genetic blueprint for our whole body-Nucleus (inner area of a cell that houses chromosomes and genes)->chromosome(threadlike structure made largely of DNA molecules)->gene(segment of DNA containing the code for a particular protein; determines our individual biological development)-Behavioral genetics:-behavior genetics: study of the power and limits of genetic and environmental influences on behavior-Environment: every non genetic influence, from prenatal nutrition to the people and things around us-Question: How to separate these effects? Is it what you were born with or how your environment shaped you?-We share 50% of our genes with each of our parents-We share 25% of our genes with each of our grandparents-We share 50% (on average) of our genes with each of our siblings; you don’t know whether youare getting the same half from each of your parents-Tend to use twin studies to answer question-Identical twin: develop from a single zygote (fertilized egg) that splits in two, creating two genetic replicas-Fraternal twins: develop from separate zygotes, genetically no closer than brothers and sisters, but they share the fetal environment-Twin studies based on a simple premise: if identical twins are more similar than fraternal twins,then it must be due to genes-Problems: identical twins may try to act differently on purpose..-How to make twin studies better: -Separated twin studies: how can we explain similarities between separated twins?. Luckor genes. If separated identical twins are more similar that separated fraternal twins, canit be due to luck?-We can also do adoption studies: if children are similar to their biological parents, it must be due to genes. If children are similar to their adoptive parents, it must be due to shared environment.-What is heritable? Just about everything. -Personality, divorce, criminality, alcoholism, smoking, political views, watching TV, happiness-Where should we see effects of genes?-Temperament: a person’s characteristic emotional reactivity and intensity; individual differences that emerge very early in life, that are likely to have a heritable basis, and that are often involved in behaviors linked with emotionality or arousablility-Should you blame your parents for who you are?-Controversial subject-Evolutionary psychology: the ancestral past determines the cognitive present; motives, strategies, and cognitive mechanisms that were adaptive for our hunter-gatherer ancestors are now built in-Steps to evolutionary psych:1. Evolution of bodies (Darwin, 1859): -Genes: are blueprints for traits (phenotypes)-Random variation: genes occasionally mutate or recombine, yielding now traits-Natural selection: traits that are maladaptive get weeded out, traits that are adaptive get passed on2. Evolution of specific behaviors and signaling systems…Ethology:-Animals have unlearned instincts, including…-Fixed action patterns (specific, pre-wired series of movements), triggeredby…-Pre-wired releasing stimuli-These pairs help solve coordination problems, example…-The problem of childcare, protective behavior from adults triggered by…cuteness (baby-like features)3. Evolution of general strategies…evolutionary psychology:-Cuteness is…large head to body ratio, small nose to face ratio, big eyes to head ratio-The problem of mating: rationality of what we find attractive, what is sexy?-Sneaky genes and the “game” of life:-From a “gene’s eye” point of view:-in the beginning there was the gene (DNA)-Genes build “survival machines” (plants, animals)-Survival machines compete-The best ones make many copies-A person is a gene’s way of making more genes-A good survival machines must...-Survive until reproductive age-ReproduceCosts Women MenTotal gametes ~4,000 ~10 trillionTotal reproductive life 25-35 years 50-65 yearsTime tied up 1-2 years 15-30 minsChance of death Yes noRearing obligation 7-18 years Optional -Benefits are half and
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