Chapter 6 Genetics. Total Assessment Guide (T.A.G.) 56, 57, 58, 59, 60, 61 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 34

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1 Chapter 6 Genetics Total Assessment Guide (T.A.G.) Topic Overview pp Nature and Nurture as Allies pp Genes and Environment as Co-actors pp Heritability of Common Personality Characteristics pp Genes and Environment: A Dialectical Synthesis pp Question Type Multiple Choice Short Answer Essay Multiple Choice Short Answer Essay Multiple Choice Short Answer Essay Multiple Choice Short Answer Essay Multiple Choice Short Answer Essay Factual Conceptual Applied 1, , , 7, 8, 11,12, 16, 17, 19 9, 10, 13, 14, 15, , 57, 58, 59, 60, 61 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, , 37, 39, 40, 41, 43, 44, 45, 50, 51 64, 65 68, 69 21, 24, , 42, 46, 48, , 52 72, 73, 74, Copyright 2012 by Pearson Education, In All rights reserve 127

2 Chapter 6: Genetics Multiple Choice A specific combination of genes is termed a(an) phenotype. genotype. DNA. allele. Difficulty: 1 Question ID: Page Reference: 140 Topic: Overview Answer: b: genotype The term for the study of genetic and environmental contributions to individual differences in personality and behavior is eugenics. evolutionary psychology. epigenetics. behavioral genetics. Question ID: Page Reference: 141 Topic: Overview Answer: d: behavioral genetics According to the textbook, the best characterization of the nature-nurture issue is that nature and nurture. That is, genes and environment can work separately, together, or they may influence one another. cooperate transact compete interact Question ID: Page Reference: 142 Topic: Nature and Nurture as Allies Answer: b: transact Copyright 2012 by Pearson Education, In All rights reserve 128

3 The manifestation of complex human traits is defined as the phenotype. genotype. homotype. gene-environment correlation. Question ID: Page Reference: 143 Topic: Nature and Nurture as Allies Answer: a: phenotype The equation used by some researchers for understanding the manifestations of complex human traits includes all of the following EXCEPT genotype. environment. epigenetics. gene-environment correlation. Difficulty: 3 Question ID: Page Reference: 144 Topic: Nature and Nurture as Allies Answer: c: epigenetics The term for the amount of observed individual differences in some characteristic that can be accounted for by genetic differences is. genotype heritability inheritance factor gene-environment co-factor Question ID: Page Reference: 143 Answer: b: heritability Copyright 2012 by Pearson Education, In All rights reserve 129

4 estimates the extent to which observed individual differences can be traced in any way to individual differences in environments. Heritability Phenotype Epigenetics Environmentality Question ID: Page Reference: 144 Answer: d: Environmentality The textbook defines environment as those aspects of the family environment that are generally the same for all the children in the househol shared common phenotypic genetic Difficulty: 1 Question ID: Page Reference: 145 Answer: a: shared All of the following are used in the textbook as examples of aspects of the nonshared environment in a family EXCEPT spacing of siblings. differential parental treatment. physical aspects of the home environment. friends. Difficulty: 1 Question ID: Page Reference: 145 Answer: c: physical aspects of the home environment. Copyright 2012 by Pearson Education, In All rights reserve 130

5 Which of the following would be the most accurate conclusion of the Finn Twin Study? For most significant behaviors, environment is the dominant factor. For most significant behaviors, genetics is the dominant factor. The relative importance of genetics and environment varies depending on the question. Modern genetic analysis makes it almost impossible to differentiate between genetic and environmental influence. Question ID: Page Reference: 146 Answer: c: The relative importance of genetics and environment varies depending on the question A fertilized egg splitting into two early in its maturation results in a nonviable zygote. two monozygotic twins. two dizygotic twins. a chimer Difficulty: 1 Question ID: Page Reference: 146 Answer: b: two monozygotic twins A synonym for fraternal twins is dizygotic twins. monozygotic twins. allele twins. heterozygotic twins. Question ID: Page Reference: 147 Answer: a: dizygotic twins. Copyright 2012 by Pearson Education, In All rights reserve 131

6 One measure of is to calculate the correlation (r) between twins on a given trait and compare the correlation between MZ twins and DZ twins. environmentality genetic strength genetic similarity heritability Question ID: Page Reference: 147 Answer: d: heritability of A second way of studying heritability, other than the formula h 2 = 2(rmz rdz) is through the use dizygotic twins reared apart. monozygotic twins reared apart. factor analysis. a quadratic analysis. Question ID: Page Reference: 147 Answer: b: monozygotic twins reared apart In the analysis of heritability, one potential problem in the double-the-difference method is that it assumes that twins do not differentially interact with each other. are the same sex. are genetically identical. are reared under equal environments. Question ID: Page Reference: 148 Answer: d: are reared under equal environments. Copyright 2012 by Pearson Education, In All rights reserve 132

7 Conclusions are often drawn about the relative importance of genetics based on the study of twins even for individuals who do not have a twin. Many twins, however are not representative of the average non-twin; many twins are born with low birth rate for example. This problem results from the assumption of representativeness. assumption of identicalness lack of care by researchers. eugenics assumption. Question ID: Page Reference: 148 Answer: a: assumption of representativeness The rmza method of estimating heritability also has its limitations. Here researchers assume that the adopted families of each twin are different form one another, but twins may be more alike on a certain characteristic due to the impact each twin has on his or her environment. communication between the two families. selective placement. representative placement. Question ID: Page Reference: 148 Answer: d: representative placement Which of the following relationships between two variables can be proven by a correlational study? Variable A causes variable B. Variable B causes variable A. A third variable (C) causes both variable A and B. None of the above can be proven by a correlational study. Difficulty: 1 Question ID: Page Reference: 150 Answer: d: None of the above can be proven by a correlational study. Copyright 2012 by Pearson Education, In All rights reserve 133

8 In the summary chart of Twin, Family, and Adopting Correlations for Neuroticism and Extraversion, the second highest correlation for Neuroticism was found in the case of identical twins reared apart. fraternal twins reared together. fraternal twins reared apart. adoptive parents and offspring. Question ID: Page Reference: 150 Answer: a: identical twins reared apart While it is unethical to devise an experiment in which you manipulate the lives of human twins, it is ethical to design an experiment involving mice twins. There are measures of mice personality characteristics. You can even purchase large numbers of mice that are genetically identical at conception in the form of cloned mice. You have been asked to design a study that looks at the contribution of genetics to anxiety in mice. Which design would best serve your goal? Random mice, raised in identical conditions Two groups of cloned mice raised in identical conditions Two groups of cloned mice each raised under different conditions Four groups of mice two random, two cloned each raised under different conditions. Question ID: Page Reference: 150 Answer: c: Two groups of cloned mice each raised under different conditions Solid, replicable research findings suggest that all of the following are at least moderately heritable EXCEPT cognitive abilities. social attitudes. psychological interests. essentially all personality variables have some degree of heritability. Question ID: Page Reference: 151 Answer: d: essentially all personality variables have some degree of heritability. Copyright 2012 by Pearson Education, In All rights reserve 134

9 Research suggests that the heritability of personality traits ranges from to. 00;.80.20;.60.40;.60.60;.80 Question ID: Page Reference: 151 Answer: c:.40; Research has suggested that the heritability of all of the big five personality factors is about 10 to 30%. 30 to 60%. 40 to 50%. 60 to 75%. Question ID: Page Reference: 151 Answer: c: 40 to 50% The textbook suggests that the environment both shared and nonshared accounts for about to % of the variance for the five personality factors discussed in the textbook. 10; 30 25; 50 45; 50 50; 60 Question ID: Page Reference: 151 Answer: c: 45; 50 Copyright 2012 by Pearson Education, In All rights reserve 135

10 Mendel is most famous for his study of the genetics of cattle. human savants. peas. roses. Difficulty: 1 Question ID: Page Reference: 153 Answer: c: peas Different forms of the same gene are known today as alleles. gene variants. elementals alters. Question ID: Page Reference: 153 Answer: a: alleles Mendelian inheritance is defined as case in which traits are crosse two recessive traits dominate over a single dominant trait. one trait dominates over another trait. all inheritance patterns are known as Mendelian. Question ID: Page Reference: 153 Answer: one trait dominates over another trait Every human being on the planet shares, on average, about what percentage of DNA? Copyright 2012 by Pearson Education, In All rights reserve 136

11 Difficulty: 1 Question ID: Page Reference: 154 Answer: d: is an area of research focusing on genetic, yet noninheritable means by which the environment fundamentally changes human functioning. Eugenics. Epigenetics. Genomics Exonics. Question ID: Page Reference: 154 Answer: b: Epigenetics A is a sequence of DNA that codes for a specific trait. genome introns gene sequence Question ID: Page Reference: 154 Answer: c: gene The coding regions of a gene are known as exons introns alleles epigenes Question ID: Page Reference: 154 Copyright 2012 by Pearson Education, In All rights reserve 137

12 Answer: a: exons The noncoding regions of genes are called introns. exons. alleles. silent sequences. Question ID: Page Reference: 154 Answer: a: introns Research has shown that people who are socially isolated are vulnerable to a host of cardiovascular and infectious diseases due to increased levels of the stress hormone cortisol. A recent study, summarized in the textbook, provides evidence that this is effected by differences in the genomes of individuals who are high in cortisol levels. diet that encourages the production of cortisol. gene expression. Mendelian inheritance. Question ID: Page Reference: Answer: c: gene expression Results of a study reported in the textbook suggest that loneliness directly impacts immune functioning by regulating the specific genes that control it. This is an example of. Mendelian genetics genomics protiamics epigenetics Question ID: Page Reference: 155 Answer: d: epigenetics Copyright 2012 by Pearson Education, In All rights reserve 138

13 Your lab is in the process of identifying gene sequences that cause mice to behave in ways that look very much like depression. As your lab is working on positional cloning, the next step in the project will be to cross-breed these mice with mice who are less prone to depression. develop a technique for replacing the gene that seems to be a causal factor in the depressive behavior. clone the mouse that shows the least amount of depressive behavior. locate the region of the brain responsible for the depressive behavior and use transcranial magnetic stimulation to increase their activity. Question ID: Page Reference: 155 Skill: Applied Answer: b: develop a technique for replacing the gene that seems to be a causal factor in the depressive behavior The textbook suggests that we could view the nature-nurture debate as a dialectic, as forces are in opposition to other, and eventually one point of view will prevail. are in different spheres of thought and therefore not related to each other. can be combined or synthesize are synonymous; they mean the same thing. Question ID: Page Reference: 156 Answer: c: can be combined or synthesize A genotype-environment occurs when a genotype responds differently to an environment. correlation differentiation interaction dialectic Question ID: Page Reference: 156 Answer: c: interaction Copyright 2012 by Pearson Education, In All rights reserve 139

14 A genotype-environment correlation occurs when a genotype and the environment act in parallel. forms a dialectic with the environment. responds differently to an environment. is exposed differently to an environment. Question ID: Page Reference: 156 Answer: d: is exposed differently to an environment The conclusion of the Russian study of the interaction between genotype and environment suggested that boys exposed to maternal rejection who also carried a specific variation of the DAT1 gene were more likely to be depressed after their experience. The conclusion the textbook draws from this research is that a variant of the DAT1 gene is the cause of depression. depression is a genetic disorder. maternal rejection is one of the causes of depression. prolonged exposure to dopamine may lead to depression. Question ID: Page Reference: 157 Answer: d: prolonged exposure to dopamine may lead to depression Anxiety, a risk factor for depression, involves a certain region of the transporter gene. dopamine serotonin GABA glucose Question ID: Page Reference: 157 Answer: b: serotonin Copyright 2012 by Pearson Education, In All rights reserve 140

15 The textbook reviews the research of Caspi, et al on men and women in New Zealan Their results suggest that an environment with more life stressors puts a person at greater risk for symptoms of depression. However, when a person with a specific genotype type genes that control serotonin transport, then the likelihood of getting symptoms of depression are greatly increase ll ss sl SlSl Question ID: Page Reference: 157 Answer: ss To date, interactions between genes and environment have been found to account for all of the following EXCEPT religious upbringing lessening the impulsiveness of high sensation seekers. parental bonding and family functioning decreasing emotional instability. close family ties increasing the level of empathy in potential psychopaths. the DRD2 gene and stress increasing the chance of alcoholism. Question ID: Page Reference: 158 Answer: c: the DRD2 gene and stress increasing the chance of alcoholism When parents provide both the genes and an environment that is favorable to the development of those genes, we observe a(n) genotype-environment correlation. active passive coordinated coherent Question ID: Page Reference: 159 Answer: passive Copyright 2012 by Pearson Education, In All rights reserve 141

16 When parents see something in a child, such as early vocalization, and respond to it with, for example, extra time vocalizing to the child, this is a genotype-environment correlation. reactive passive logical respondent Question ID: Page Reference: 159 Answer: a: reactive In some situations parents provide a genotype to a child (such as genes that enhance language development), an environment where books an conversation are available, and the child chooses activities that are language base The textbook labels this a genotype-environment correlation. consistent positive maximal natural Question ID: Page Reference: 160 Answer: b: positive In a negative genotype-environment correlation with regard to language development a child has inherited genes that are not favorable for language development. a child has inherited genes that are favorable to language development but the environment he or she has been provided discourages language development. a child has inherited genes that are favorable to language development and opportunities in the environment to practice language development but chooses not to participate. a child has inherited genes that are not favorable for language development and is in an environment that discourages language activities. Question ID: Page Reference: 161 Answer: b: a child has inherited genes that are favorable to language development but the environment he or she has been provided discourages language development. Copyright 2012 by Pearson Education, In All rights reserve 142

17 Research reported in the textbook suggests that an example of reactive-genotype-environment correlation is supported by evidence that more aggressive children who are raised by firm but supportive parents are less aggressive as adults. children at risk for antisocial behavior are more aggressive than children not at risk, and they are more likely to elicit negative reactions in their parents. children not at risk for antisocial behavior can exhibit considerable aggressive behavior after only one year in an aggressive family, certain gene variations invariably lead to increased aggression in children. Question ID: Page Reference: 161 Skill: Applied Answer: b: children at risk for antisocial behavior are more aggressive than children not at risk, and they are more likely to elicit negative reactions in their parents Research by Burt suggests that genes can code for a particular behavior, but not the social consequences of that behavior. can code for social consequences of a particular behavior, but not the behavior itself. can code for a particular behavior and for the social consequences of that behavior. can t code either for a particular behavior or social consequences. Question ID: Page Reference: 162 Answer: c: can code for a particular behavior and for the social consequences of that behavior Examples of gene-environment are many and include all of the following EXCEPT adolescents perceptions of parental warmth. family coherence and psychopathy. physical punishment and misbehavior. memories of childhood environment/ Question ID: Page Reference: 162 Answer: b: family coherence and psychopathy. Copyright 2012 by Pearson Education, In All rights reserve 143

18 The textbook lists several research goals for current genetic research that include all of the following EXCEPT improved in intelligence. medical treatments individually tailored to an individual s DNA cures for cancers and other diseases. a better understanding of evolution. Question ID: Page Reference: 163 Answer: a: improved intelligence Genetic research is feared by some people because of the excesses of the movement. progenics eugenics epigentics genomics Question ID: Page Reference: 163 Answer: b: eugenics Your research has focused on the cause(s) and prevention of depression. As you are current on the literature focused on the genetics of depression, it is likely that you will be gathering data on genes that correlate with depression. gene environment interactions that correlate with depression. eugenic data combing environmental and genetic issues. the environments that correlate with depressive episodes. Question ID: Page Reference: 163 Skill: Applied Answer: b: gene environment interactions that correlate with depression. Copyright 2012 by Pearson Education, In All rights reserve 144

19 Short Answer The general field that looks at questions of how genes and environments work together is known as. Question ID: =3 Page Reference: 141 Topic: Overview Answer: behavioral genetics The textbook suggests that the best way to characterize nature-nurture issues is to suggest that the two. That is, genes and environment work both separately and together, and sometimes they influence or change one another. Question ID: Page Reference: 142 Topic: Nature and Nurture as Allies Answer: transact The manifestation of complex human traits is known as a. Question ID: Page Reference: 143 Topic: Nature and Nurture as Allies Answer: phenotype (h2) is defined as the amount of observed individual differences in some characteristics that can be accounted for by genetic differences. Difficulty: 1 Question ID: Page Reference: 143 Answer: Heritability Copyright 2012 by Pearson Education, In All rights reserve 145

20 (e2) is an estimate of the extent to which observed individual differences are caused by environmental factors. Difficulty: 1 Question ID: Page Reference: 144 Answer: Environmentality Aspects of the family environment that are generally the same for all the children in the family make up the environment Difficulty: 1 Question ID: Page Reference: 145 Answer: shared Identical or twins that come from the fertilization of one egg by one sperm. Question ID: Page Reference: 146 Answer: monozygotic Twins that are the product of the fertilization of two eggs by two sperm often at the same time are called fraternal or twins. Question ID: Page Reference: Answer: dizygotic It is likely that people treat MS twins in a manner that is quite similar in many aspects. This is an example of the assumption. Question ID: Page Reference: 148 Copyright 2012 by Pearson Education, In All rights reserve 146

21 Answer: equal environments The new field of has found ways in which the environment can fundamentally change human functioning by altering gene expression without altering what DNA is inherite Question ID: Page Reference: 154 Topic: Heritability of Common Personality Characteristics Answer: epigenetics Research has established that people who are socially isolated are vulnerable to a host of cardiovascular and infectious diseases due to increased levels of the stress hormone. Question ID: Page Reference: 154 Topic: Heritability of Common Personality Characteristics Answer: cortisol A potential genetic risk factor for depression, anxiety, and other mood disorders involves a certain region of the transporter gene. Question ID: Page Reference: 157 Answer: serotonin When parents provide both the genes and an environment that is favorable (or unfavorable) to the development of those genes, we observe a genotype-environment correlation. Question ID: Page Reference: 159 Answer: passive Research has found that children at risk for antisocial behavior are indeed more aggressive than children not at risk, and they are also more likely to elicit negative reactions in their caregivers. This is an example of a genotype-environment correlation. Copyright 2012 by Pearson Education, In All rights reserve 147

22 Question ID: Page Reference: 161 Answer: reactive Essay Briefly describe the difference between a human genotype and a phenotype, as well as their relationship. Question ID: Page Reference: Topic: Nature and Nurture as Allies Answer: The human genotype is the set of genes, in the form of DNA, that an individual inherits from his/her parents. The phenotype is the manifestation of human characteristics that are a function of the interaction of the genotype and the environment. For example, a person may be born with genes that will allow that individual to develop a great ability to understand and manipulate language, but if they are not exposed to language from a very young age their language genes will go wasted and their phenotype may lack language ability almost entirely Compare and contrast the concepts of shared and nonshared environment with an example relevant to personality development. Question ID: Page Reference: 145 Answer: Researchers often investigate the effects of the environment on the development of personality. It used to be that any part of the phenotype that was not accounted for by genes was assumed to be due to the environment. Now researchers are interested in the dynamics of the environment. It has been identified that even if two people are in the same household or school they may not necessarily experience the same environment. One way of describing this is to define characteristics of an environment that essentially the same for two children. These aspects would be identified as shared environmental factors. If parents create an atmosphere of tolerance, for example, and are quite consistent about its application to two children this is part of their shared environment. In contrast, one child in a family may be treated as if they are quite bright and another, for various reasons, may be treated as if they are slow. [There are many ways of addressing this and many examples that students can use; the basic definitions are the key feature for this question.] Copyright 2012 by Pearson Education, In All rights reserve 148

23 Discuss the methodological importance of MZA twins. Question ID: Page Reference: Answer: MZA twins are monozygotic twins reared apart. This is an extremely important group of individuals for a variety of research projects including many focused on personality development. Monozygotic twins start off genetically identical as they are derived from one egg fertilized by one sperm that splits into two zygotes very early in development. If monozygotic twins are reared in the same family and school then there is the possibility that neither their genome nor their environment are much different. If, however, they are adopted into two different families then there is the possibility that their environments are different. If their genomes are very close to identical then any differences in personality may be attributed to environmental forces Discuss the meaning of epigenetics and its importance for the study of personality. Question ID: Page Reference: Topic: Heritability of Common Personality Characteristics Answer: Epigenetics is a relatively new field of study. It is the study of the ways in which the environment can influence the expression of genes, or the genetic component of development, in a way that does not alter heritability. A gene is a sequence of DNA that codes for a specific protein, or trait. A given gene has coding regions called exons and noncoding regions called introns. Of all the DNA in a cell, only 3% or so is composed of functioning genes. The rest (97%) used to be called junk DNA, but at least some of this junk performs a very important function regulating the expression of genes; some of this function is influenced by the environment. This means that the environment can have influence over which genes in a cell or set of cells are expressed, or use An example of some research into this process is the Cole study that demonstrated that different genes were expressed in individuals who were lonely compared to another group that was not lonely. Genes that had the effect of preventing disease were less expressed in individuals who were also deemed lonely Discuss how you might investigate one personality problem with an eye to using positional cloning to prevent that problem. Question ID: Page Reference: 155 Topic: Heritability of Common Personality Characteristics Skill: Applied Answer: Positional cloning is a process by which a given gene can be altered by replacing either the whole gene or a portion of the gene to alter the result of the expression of that particular gene. If we targeted one personality factor, say the lack of empathy, which is associated with behaving badly to other people, we might be able to find the gene responsible for that particular personality characteristi If we then identified an allele that correlated with high empathy and another correlated with being low in Copyright 2012 by Pearson Education, In All rights reserve 149

24 empathy and discovered the difference between the two, we might be able to either replace or alter the allele that correlates with low empathy. Hopefully this would make it more likely that the individual would have the functionality that makes it possible to understand and feel the emotions of others. [Obviously there are a host of hypothetical examples that a student might use to answer this question.] What does the textbook mean by a dialectical synthesis of nature and nurture? Question ID: Page Reference: Answer: For Hegel a dialectic was a way of thinking that synthesized or combined contradictions into a unified whole. If nature (genetics) and nurture (environment) are seen as complementary to each other as having mutual influence on each other then the so-called nature-nurture debate ceases to exist. A good example of this synthesis is in epigenetics. If the environment can alter which genes are expressed or the extent to which a given set of genes is expressed then the environment and genetics are interacting. The equation used in the book is that the phenotype (the observed characteristics of an individual) are equal to the genotype + the environment + the gene-environment correlation + the gene-environment interaction Compare and contrast genotype-environment correlation with genotype-environment interaction. Question ID: Page Reference: Answer: A genotype-environment interaction occurs when a genotype responds differently to a given environment. A genotype-environment correlation occurs when a genotype is exposed differently to an environment. An example of the former from the book is the study of Russian juvenile delinquents, the majority of which had experienced maternal rejection; only those with a particular genotype experienced clinical depression as a result of this environmental event. That group carried a gene that is fragile to exposure to the excess dopamine that is often the result of rejection. An example of genotypeenvironment correlation is one in which a group of infants seek out verbal interaction with caregivers as a result of their genes. Here they are not passive, but are genetically encouraged to behave in a particular way Compare and contrast a positive genotype-environment correlation with that of a negative genotype-environment correlation. Question ID: Page Reference: Answer: In a genotype-environment correlation, an individual s genotype affects the type of environment in which they find themselves. All of us, to certain degree, construct our own environments both in reality and in our memory of those environments. In an active-genotype-environment correlation parents or Copyright 2012 by Pearson Education, In All rights reserve 150

25 grandparents have provided both the genes and the environment. When that environment is favorable for the development of a given characteristic, derived in part from genes that also encourage the characteristic, then it is termed a positive genotype-environment correlation. If the conditions work against the genes for a given characteristic it is termed a negative genotype-environment correlation Summarize one piece of evidence that supports the genotype-environment correlation model. Question ID: Page Reference: Answer: There are several examples in the textbook from which the students may draw. One example is the Narusyte, et al (2007) study which found that childhood aggression is related to parental criticism that was, in turn, related to self-reported antisocial behavior in adolescence. They suggested that this was an example of genotype-environment correlation since children at risk for antisocial behavior are more aggressive than children not at risk for this behavior and are, at the same time and as a result of their behavior, more likely to elicit negative reactions from caregivers Outline a research project that would follow from the observations and conclusions regarding gene-environment correlations in the work of Burt. Difficulty: 3 Question ID: Page Reference: 162 Skill: Applied Answer: Burt s research involved observations that men who had a G-allele that made them more likely to break rules and take risks would induce liking on the part of others. It seems that rule breaking does lead to popularity. There are other possible interactions in this line of research that may involve similar gene-environment interactions. Social dominance, for example, is widely studied and it is likely that one or more genes may be correlated with behaviors that lead to social dominance. Once this gene or these genes are identified then one could look for reactions from those socially dominate It could even be that a gene for being social dominated could be identified and then a gene-gene-environment interaction could be studie [There are many possible combinations that a student could discuss. The answer needs only to demonstrate a basic knowledge of possible gene-environment interactions.] Copyright 2012 by Pearson Education, In All rights reserve 151