{"id":4324,"date":"2018-09-18T22:30:01","date_gmt":"2018-09-19T02:30:01","guid":{"rendered":"https:\/\/www.amyork.ca\/academic\/zz\/?p=4324"},"modified":"2018-09-18T22:37:52","modified_gmt":"2018-09-19T02:37:52","slug":"heredity-or-environment-genetics","status":"publish","type":"post","link":"https:\/\/www.amyork.ca\/academic\/zz\/evolutionary-psychology\/heredity-or-environment-genetics\/","title":{"rendered":"Heredity or Environment \u2013 Genetics"},"content":{"rendered":"<p>2 verities of animal studies<\/p>\n<ul>\n<li>Selective breeding studies: manipulate heredity which keeping environment constant \uf0b7 Mice: breed 2 mice high in traits and low in traits.<\/li>\n<li>Raise the animal over several generations. Raise animals with high trait A and those high trait B. measure degree to which they vary = amount due to heredity.<\/li>\n<\/ul>\n<p>In breeding = manipulate environment while genetics remain constant. Breed offspring back to parents. About 20 generations. Get identical = any changes are due to environment.<\/p>\n<p>Condition 1: hereditary difference and environment constant.<\/p>\n<ul>\n<li>Difference found for height in mice = .90. (reared apart) Example where heredity is affected by environment<\/li>\n<\/ul>\n<p>Fraternal twins raised in the same household or identical twins in the same household.<\/p>\n<p>\uf0e0 Get as much similarity in environment, but fraternal twins share an average of 50% of genes in common whereas identical twins is 100% of their genes in common.<\/p>\n<ul>\n<li>If there is a different between identical twins and fraternal then heredity would be part of that.<\/li>\n<li>Fraternal twins in height: .45<\/li>\n<li>And identical reared APART: .90<\/li>\n<\/ul>\n<p>\uf0b7\u00a0\u00a0\u00a0\u00a0\u00a0 You know that genetics are involved.<\/p>\n<p>Siblings are reared apart from birth. Environments are not similar:<\/p>\n<ul>\n<li>The correlation between twins apart is the same as twins reared together.<\/li>\n<li>No effect of shared environment: being raised in the same household.<\/li>\n<\/ul>\n<p>Fraction that determines the role of genetics \uf0e0 heritability<\/p>\n<p>Def\u2019n: the proportion of phenotypic variation is due to genotypic variation.<\/p>\n<ul>\n<li>How much of the difference between individuals is based on heredity.<\/li>\n<li>How do we measure this? The correlation between identical twins reared apart on some traits. \uf0b7 Assume they have no been adopted into families that are like their biological ones \uf0b7 Any attribution of a trait is due to heritability.<\/li>\n<\/ul>\n<p>Randomly match between 2 pairs \uf0e0 assume there is a degree of association is heredity.<\/p>\n<p>Environments of identical twins are not always identical.<\/p>\n<p>Correlation of identical twins reared together, and fraternal twins reared together \uf0e0 heritably can be calculated in a simple equation.<\/p>\n<p>Fraternal twins: half the genetic influences, plus all the influences of shared environment.<\/p>\n<p>Identical twins: genetic influences and influences of shared environment<\/p>\n<p>What is the heritability of height based on? Subtract fraternal twins by identical twins and then double it.<\/p>\n<p>Uncorrelated environments: IQ. Heritability for IQ.<\/p>\n<p>Identical twins reared apart: correlation is .72 which is quite high.<\/p>\n<p>Identical twins reared together: .86<\/p>\n<p>Fraternal twins reared together: .60<\/p>\n<ul>\n<li>Subtract .60 from .86 and then double it \uf0e0 .52. a more accurate assessment of HERITABILITY OF IQ.<\/li>\n<li>Half heredity, half environment<\/li>\n<\/ul>\n<p>Compare adopted children with their biological and adopted parents.<\/p>\n<ul>\n<li>Half siblings with full siblings.<\/li>\n<li>Can see if they are raised together or apart.<\/li>\n<\/ul>\n<p>More advanced statistical methods which give them more advanced measures which show the end of genetic variance.<\/p>\n<p>Additive variance: computable linear relationships Nonadditive: no interaction of any sort.<\/p>\n<p>Data of the traits studied by psychologists<\/p>\n<p>Widest studied trait is IQ: convienent, available, encompasses a wide range of things.<\/p>\n<ul>\n<li>As people get older, heritability of IQ increases, in middle childhood and adolescence.<\/li>\n<li>The older the group, the more heritability will show.<\/li>\n<li>Parents are less involved with their kids as they are older, so the biological influences take over.<\/li>\n<li>As adopted children get older, their IQ and intelligence will become more like their parents. As children got older, they wanted to meet their parents.<\/li>\n<li>Twins raised apart, reunited, you can see the nuances of behaviour that they show.<\/li>\n<\/ul>\n<p>Many studies on cognitive inheritability: .30 &#8211; .50 for verbal comprehension, fluency, spatial visualization, verbal reasoning etc.<\/p>\n<p>Reading ability: .30 upward<\/p>\n<p>Personality \u2013 most studies focused on 3 traits. Eysneck\u2019s theory which was that personality had 3 components<\/p>\n<ul>\n<li>Emotionality \u2013 tendency to have arousing emotions<\/li>\n<li>Extraversion<\/li>\n<li>Activity level<\/li>\n<\/ul>\n<p>.30 or higher using the Kreuger method (?). Minnesota project.<\/p>\n<p>To get estimates of .50 and .75, it includes optimism (sensibility). This is the most heritable personality trait. \uf0e0 .82 Others:<\/p>\n<ul>\n<li>Leadership<\/li>\n<li>Social closeness<\/li>\n<li>Alienation<\/li>\n<li>Aggression<\/li>\n<li>Self-control<\/li>\n<li>Altruism\/empathy<\/li>\n<li>Nurturance<\/li>\n<\/ul>\n<p>(Moderate number of inheritability).<\/p>\n<p>\uf0b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Political conservatibility \uf0e0 .30 and .50.<\/p>\n<p>&#8211;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Does not mean there is a gene for this, but there may be heritable traits that cause this.<\/p>\n<p>Heritability for the 2 major forms of psychosis<\/p>\n<ul>\n<li>Schizophrenia (manic depressive)<\/li>\n<li>Bi polar disorder<\/li>\n<\/ul>\n<p>Shyness and aggression do have reasonably high heritability traits<\/p>\n<p>\uf0e0 Also a high hereditability for criminal acts, because of testosterone level \u2013 genetically determined.<\/p>\n<ul>\n<li>This makes you more aggressive.<\/li>\n<\/ul>\n<p>High T and raised in a low-socio economic environment, you will have a higher aggression. If you are raised with high T in a middle class society then you are likely to have less criminal activity.<\/p>\n<p>Estimates vary between 50-60 % for most traits, but a lot of study shows nill effects of heritability in shared environments. The correlations for siblings apart are the same as those reared together.<\/p>\n<ul>\n<li>For unrelated siblings reared together, tend to be nill. Similarities of the environment do not account in themselves for personality similarities.<\/li>\n<li>Antithetical to personality development theories.<\/li>\n<li>Siblings reared apart have the same correlations as siblings reared together.<\/li>\n<li>Can have the same environment but different treatment in the environment.<\/li>\n<li>Know key percentages, ex. Heritability is 50. Not every individual personality trait.<\/li>\n<\/ul>\n<p>Vp (variance of pheotype)\/Vg(variance of genetics) this is simple heritability or H squared.<\/p>\n<p>The minus and doubling is a more accurate measurement of heritability than the simple measure. Additative hereditability: multiple genes at the same locus that can contribute to the same trait.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>2 verities of animal studies Selective breeding studies: manipulate heredity which keeping environment constant \uf0b7 Mice: breed 2 mice high in traits and low in traits. Raise the animal&hellip; <a class=\"continue\" href=\"https:\/\/www.amyork.ca\/academic\/zz\/evolutionary-psychology\/heredity-or-environment-genetics\/\">Continue Reading<span> Heredity or Environment \u2013 Genetics<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[109],"tags":[],"_links":{"self":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts\/4324"}],"collection":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/comments?post=4324"}],"version-history":[{"count":0,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts\/4324\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/media?parent=4324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/categories?post=4324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/tags?post=4324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}