Unit # 1: Course Introduction and OverviewOverview: Unit # 1 provides an overview to the field of human behavioral genetics and to this course. We will begin by discussing the early history of the field and how behavioral genetic research influenced and was influenced by the eugenics movement. Once this historical context has been established, we will define the field of behavioral genetics and use this definition to provide an overview of the course. This week’s lectures will end with two case studies that illustrate the importance of behavioral genetic approaches. The first is the famous John/Joan case, where one member of a monozygotic twin pair was raised as a boy and the other as a girl. The second is the human genetic disorder Phenylketonuria (PKU), which has been recognized as a paradigm of human genetic disease since its discovery in 1934.Unit Objectives: At the end of this unit you should know• The history of the founding of the field of behavioral genetics• What the eugenics movement was and how it impacted psychology and behavioral genetics• What the field of behavioral genetics covers• How the John/Joan case represented the extreme of the “Blank Slate” mentality within psychology• Why Phenylketonuria is considered a public health success and model of human genetic diseaseLecture Modules:A. The Nature-Nurture Debate and Founding of Behavioral GeneticsB. The Eugenics MovementC. What is Behavioral GeneticsD. The John/Joan CaseE. Phenylketonuria (PKU) F. Huntington Disease (Supplemental)

In Unit #2 the twin study method will be introduced and general findings from twin studies in psychology and psychiatry will be reviewed. The two types of twins, monozygotic (MZ) and dizygotic (DZ), will be described and methods for assessing their similarity will be given. We will also look critically at the limitations of the twin study method and discuss alternative research designs, including adoption studies and the study of reared-apart twins. The importance of convergent evidence from multiple research designs will be emphasized.

Some of the most contentious issues in behavioral genetics surround the concept of heritability – Is it a meaningful statistic? Can it be accurately estimated in studies on humans? How should it be interpreted? In this unit we will discuss what is meant by heritability and describe some simple biometric (i.e., quantitative genetic) methods used for it estimation. The unit begins with a review of basic Mendelian inheritance and the introduction of some genetic terminology we will begin to use in the course. The ACE model of quantitative inheritance is described and we will discuss how this model is used to analyze twin data. Finally, the important concept of gene-environment interaction is formally introduced. Beginning this week with quantitative genetics and continuing next week with molecular genetics we will be jumping head first into the thicket of human genetic methodology. For some, this material may be more challenging than that which we covered in the first two weeks of this course. These weeks will, however, provide the foundation we will need to investigate in depth behavioral genetic research on schizophrenia and intelligence in weeks 5 and 6. Please make sure to post questions you have to the discussion forums and especially to the office hours forum.

The Human Genome Project (HGP) was begun in 1990 and declared complete in 2003. It has revolutionized our understanding of genetics and will ultimately revolutionize medical practice. In my opinion, every educated citizen should know some basic findings from the HGP. This week’s lectures provide an introduction to molecular biology and the HGP. We will cover topics such as: What is DNA? What is a gene and how are genes structured? In what ways can human genomes differ? What is epigenetics and why do some researchers believe it is very important for understanding behavior? As in previous lectures, I will illustrate some of the basic human genetic phenomena through case studies, in this case ranging from calico cats to the human genetic disorders of Angelman and Prader-Willi syndromes. This week’s lectures continue what we began last week: laying the foundation of genetic concepts and processes we will need to consider in some depth genetic research on schizophrenia and intelligence. Some participants in this course already have an extensive background in basic genetics and so will be very knowledgeable about material covered in the initial modules. But I think even these participants will have something to learn when we get to the later modules in the unit covering, e.g., Williams Syndrome, Prader-Willi Syndrome and Angelman Syndrome. For those with a more limited background in genetics, I recognize that the terminology introduced this week may at first seem a bit daunting. But if you stick with it, terms such as SNPs, methylation, exon, copy number variants, etc. which seem foreign now will become consolidated in your vocabulary through repeated use throughout the remaining lectures in this course. There are several learning aids I would encourage you to use. First, we have created a Glossay, which you can link to off the navigation bar on the course website. Second, the Discussion Forums are a wonderful source of help. Other participants can be very helpful in answering your questions and a post in the Office Hours thread will be reviewed by us for response in the weekly office hour video. Finally, we give again online genetics education links in the Other Resources section below.