Table Of ContentEHAVIOR GENETICS
.
Sixth Edition
Robert Plomin
Institute of Psychiatry
London
John C. DeFries
University of Colorado
Boulder
Valerie S. Knopik
Rhode Island Hospital and Brown University
Jenae M. Neiderhiser
Penn State University
Worth Publishers
New York
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BEHAVIORAL GENETICS
Contents
About the Authors xv
Preface xvii
D
Overview 1
D
Mendel's Laws of Heredity 6
Mendel’s First Law of Heredity 7
Gregor Mendel’s Luck 8
Huntington Disease 10
Phenylketonuria 11
How Do We Know That 1 in 50 People Are
Carriers for PKU? 13
Mendel’s Second Law of Heredity 14
Summary 18
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Beyond Mendel's Laws 20
Genes on the X Chromosome 21
Other Exceptions to Mendel’s laws 23
New Mutations 23
Changes in Chromosomes 23
Expanded Triplet Repeats 25
Genomic Imprinting 26
Complex Traits 28
Schizophrenia 28
General Cognitive Ability 29
Pea Size 30
Multiple-Gene Inheritance 32
Quantitative Genetics 34
Liability-Threshold Model of Disorders 36
Summary 38
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DNA: The Basis of Heredity 39
DNA 39
B«i*Ki ’ The “Central Dogma” of Molecular Genetics 44
Chromosomes 46
Summary 49
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Animal Models in Behavioral Genetics 50
Quantitative Genetic Experiments to Investigate Animal Behavior 50
Selection Studies 52
Inbred Strain Studies 57
Animal Studies for Identifying Genes and Gene Functions 60
Creating Mutations 61
Quantitative Trait Loci 66
Synteny Homology 71
Summary 71
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Nature, Nurture, and Human Behavior 73
Investigating the Genetics of Human Behavior 74
Adoption Designs 74
BOX 6.1 The First Adoption Study of Schizophrenia 77
BOX 6.2 Issues in Adoption Studies 78
Twin Design 78
BOX 6.3 The Twin Method 82
Combination 84
Summary 85
CHAPTE
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Estimating Genetic and Environmental Influences 86
Heritability 86
Interpreting Heritability 89
BOX 7.1 Estimating Quantitative Genetic Parameters
Directly from DNA 90
Environmentality 95
Shared Environment 96
Nonshared Environment 96
Estimating Shared and Nonshared Environmental Influences 97
Identifying Specific Nonshared Environment 98
Identifying Specific Nonshared Environment That Predicts
Behavioral Outcomes 100
Multivariate Analysis 102
Summary 103
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The Interplay between Genes and Environment 105
Beyond Heritability 106
Genotype-Environment Correlation 107
The Nature of Nurture 108
Three Types of Genotype-Environment Correlation 111
Three Methods to Detect Genotype-Environment Correlation 112
Implications 117
Genotype-Environment Interaction 118
Animal Models 120
Adoption Studies 120
Twin Studies 122
DNA 123
Summary 126
Identifying Genes 128
Mutations 129
Detecting Polymorphisms 130
DNA Markers 132
Human Behavior 134
Linkage: Single-Gene Disorders 135
Linkage: Complex Disorders 137
Association: Candidate Genes 137
Affected Sib-Pair Linkage Design 138
Association: Genomewide 139
SNP Microarrays 140
Summary 143
D
Pathways between Genes and Behavior 144
U23B0DI Levels of Analysis 145
Gene Expression and the Role of Epigenetics 146
The Transcriptome: Gene Expression throughout the
Genome 149
Gene Expression Profiles: RNA Microarrays and
Sequence-Based Approaches 149
Genetical Genomics 151
Gene Expression as a Biological Basis for Environmental
Influence 152
The Proteome: Proteins Coded throughout the Transcriptome 153
The Brain 155
Endophenotypes 156
Learning and Memory 157
Emotion 160
Summary 162
n
Cognitive Disabilities 163
General Cognitive Disability: Quantitative Genetics 164
General Cognitive Disability: Single-Gene Disorders 165
Phenylkonuria 165
Fragile X Syndrome 166
Rett Syndrome 168
Other Single-Gene Disorders 168
General Cognitive Disability: Chromosomal Abnormalities 170
Down Syndrome 170
Sex Chromosome Abnormalities 171
Specific Cognitive Disabilities 174
Reading Disability 175
wzsm wM DF Extremes Analysis 176
Communication Disorders 180
Mathematics Disability 181
Comorbidity among Specific Cognitive Disabilities 181
Dementia 181
Summary 183
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General Cognitive Ability 186
Historical Highlights 188
Animal Research 188
Francis Galton 190
Human Research 193
Overview of Genetic Research 194
Genetic Influence 194
Environmental Influence 196
Assortative Mating 197
Nonadditive Genetic Variance 198
Developmental Research 200
Does Heritability Change during Development? 200
Do Genetic Factors Contribute to Developmental
Change? 204
Identifying Genes 206
Summary 209
Specific Cognitive Abilities 210
Broad Factors of Specific Cognitive Abilities 210
Multivariate Genetic Analysis 217
Information-Processing Measures 218
Working Memory Model 220
Imaging Genetics 220
School Achievement 222
Identifying Genes 228
Summary 229
Schizophrenia 230
Family Studies 231
The Beginnings of Psychiatric Genetics:
Bethlem Royal and Maudsley Hospitals 232
Twin Studies 234
Adoption Studies 236
Schizophrenia or Schizophrenias? 238
Identifying Genes 239
Summary 241
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Other Adult Psychopathology 242
Mood Disorders 242
Family Studies 243
Twin Studies 245
Adoption Studies 246
Identifying Genes 247
