Hello, and welcome to an Introduction to Human Behavioral Genetics. My name is Matt McGue, and I am honored to be the instructor for this course. I am very much looking forward to having this time with you to discuss my area of psychology, behavioral genetics. This course will run for the next eight weeks. And each week will consist of a lecture unit, a quiz, one or two readings, and an opportunity to participate in a discussion forum. Each lecture unit will consist of usually from four to six modules. With each module running approximately ten to 15 minutes in length. This first module will provide a historical introduction to the course. It actually consists of five units. The the way I've organized this first lecture unit really reflects, I think two features of my approach to the field of behavioral genetics. First of all, rather than just telling you about where the scientists today, one of the things I like to do is place in his, historical context. I think in doing that, what students begin to learn about is that, science doesn't progress in some nice, linear, monotonic way, but we have fits and starts, and we sometimes regress. And I think by looking at the historical context of behavior genetics, you'll get a better understanding, not only of how the field has evolved over the last 100 years, but also how it is that we came to be where we are today. So actually, this, in this first lecture unit, the first two modules will be providing a historical context for the field of behavioral genetics. only then, will I actually give you a formal definition of what I think the field of behavioral genetics is about, and provide an overview of the specific topics I'm hoping to cover in this course. Finally, the second characteristic of my approach to teaching behavioral genetics, is rather than in the abstract, giving you definitions of concepts. Although I will be doing some of that. Definitions of concepts. I'd like to introduce concepts principles through illustrative examples. These might be case studies, or very informative human genetic syndromes. Or even a single study in behavioral genetics that we'll look at in some detail. So in this first lecture unit, the last two modules will actually be examples. One where we look at a very famous twin study called the John/Joan case, and then finally a very important human genetic condition called phenylketonuria. But this first unit we'll learn about the historical founding of behavioral genetics, both as an outgrowth of the nature-nurture debate and about Francis Galton, the founder of behavioral genetics. Some of Francis Galton's students, as you will see, took his position to an extreme, to extreme and advocated that the ideology of genetic determinism, that ultimately I think, undermined some of Galton's original goals. One of the unique features of humans is our diversity. We are an extraordinarily diverse, we differ among each other on many dimensions, on many traits. Some of us are tall, others of us are short. More to the point of this course, some of us are happy and outgoing, others sullen and withdrawn. Some of us suffer psychotic illnesses, while others will go through life without any mental health problems. Philosophers, scholars, researchers, scientists have for thousands of years speculated about the origins of these individual differences among us. One hint to the origins of individual differences in not only our physical qualities, but also our psychological qualities, comes from the observations that many of these individual differences aggregate in families. That is, if you took two family members, they're more likely to be similar on a particular dimension or trait than two randomly, randomly selected individuals in the population. And this can be illustrated through a reference to a very famous American family, the Kennedys. The Kennedys are notable, in terms of them, in terms of them being quite physically attractive as a family. The sons as well as the daughters. But they're also notable in terms of their psychological similarity. They're a very intelligent family. They're a very ambitious family, following after Joe the patriarch. And they're a very politically engaged family. The observation that resemblances among us aggregate in families has been taken advantage of by humans for over eight, nine, 10,000 years, and began with the selective breeding of domesticated animals. One of the best illustrations that behavior can be inherited is the demonstration that through selective breeding, we could produce different dog breeds. Dog breeds have been selected for eight, eight, from eight to 10,000 years. And there have been, and they have been selected not only in terms of physical quality, size, but also in terms of their behavioral qualities. Cocker Spaniels were selected to be friendly, terriers to ferret out small animals in burrows, and retrievers to fetch downed game. The Classicists, the Greeks observing the success of selective breeding programs attempted to take that success and apply it to social and public policy. Plato, who I would say is probably the first known eugenicist. A term we'll come back to a little bit later today. Plato, in designing his ideal society, argued that what society should do is try to identify the best males and the best females, and have them mate. In fact, he developed something he called the marriage quotient, to try to identify which men and which women should actually be allowed to mate. His student, Aristotle, was concerned about mating of people he didn't think should mate, that had various physical as well as behavioral deformities. [BLANK_AUDIO] The first use of the term nature and nurture to define the debate that it gone on for centuries millennium, probably owes to the greatest psychologists of all time. Someone that if you've taken a psychology course before, you may not have heard of in your psychology course but you know him well. Shakespeare. Shakespeare describes Caliban in The Tempest as a devil, a born devil, on whose nature nurture could never stick. Shakespeare was a hereditarian, and it's never been said better or more beautifully than he said it here. While Shakespeare may have been the first to use the, felicitous terms nature and nurture to describe the essence of the debate as to the origins of the individual differences among us. The nature-nurture debate is most strongly identified with this man, Sir Francis Galton. Who lived in the nineteenth and early twentieth century, a Victorian gentleman. Galton was Darwin, Charles Darwin's first cousin. He was a brilliant man, a polymath by any definition of that term. He founded the field of behavioral genetics, individual differences or differential psychology. He developed a whole area of statistics called biometry, or biometrics. And in founding the field of behavioral genetics, he did this by starting the first, or doing the first behavioral genetics study. Galton when, his cousin, when Darwin published his magnum opus in 1859, The Orgin of the Species, Galton took this as defining his life work. What Galton was interested in is applying Darwinian principles to the developing field of psychology. In the late 19th century, psychology was differentiating out of philosophy, and Galton saw this as an opportunity to found this new field of psychology on the principles his cousin articulated in The Origin of the Species. So in 1869, he actually did the first beha, large scale behavioral genetic study. The study is called Hereditary Genius, and he published it in a book in 1869. And what Galton did is he took what he considered eminent men. These could be humanous, poets, philosophers, scientists, politicians, military men. He only studied men because of the recognition that in Victorian England women were women's opportunities to achieve socially were constrained. But he started with these men and then he studied their relatives. And what he observed was that by his definition of eminence, one out 4,000 men were eminent. But if you looked at the second and first degree relatives, he saw very strong familial resemblance for eminence. Indeed, among the first degree relatives of eminent men, he saw a 1,000 fold increase in the rate of eminence. Eminence ran in families. Now Galton was no fool, he recognized that eminence could run in families not only because of nature, what we today call genetics, as well as nurture, their environment. But he had counter arguments against the explanation that the aggregation, the familial aggregation of eminence was simply a function of nurture. I won't go through all of these, but I'll just mention one. He used, for example, case studies. Individuals like Michael Faraday. Michael Faraday was the most eminent physicist of the 19th century, developed field theory. But Michael Faraday grew up in poverty, he really was self taught. And Galton argued it, how could you explain someone like Michael Faraday through a nurture argument? But mostly, Galton did and what he's really famous for, is establishing the field of individual differences in behavioral genetic psychology. He did this by collecting a lot of data. He established an anthropermetric laboratory in, in London, and he collected physical measurements and measurement of cognitive functioning, and he looked at family resemblance. And at the end of his, towards the end of his career, Galton came to the conclusion in an off cited quote, that there is no escaping from the conclusion that nature prevails enormously over nurture. Nature being what we would today call genetics, so the term genetics wasn't available to Galton in the 19th century, and nurture our rearing environment. Galton believed based upon the research he did, that nature was the predominant source, or origin of individual differences in behavior. But Galton did not entirely dismiss the importance of nurture. If you continue on in the quote, it's a, it's an acknowledgement by Galton that nurture was also, or is also important in determining our individual differences in behavior. If, for example, you took individuals living in the extreme in poverty versus affluence in England at the time, then certainly that had an impact on their behavior, and Galton recognized this. For him, nature or our genetics was a very important determiner of individual differences within what we might today call the broad middle class. But that nurture was also to some degree important. By the end of his career, Galton was successful in establishing psychology as a Darwinian discipline. But ultimately, he failed. And he failed for two reasons. The first is that, while Galton allowed that nurture was important in certain circumstances, many of his students or disciples did not. They took the nature position to an extreme. And one illustration of this is a very famous early developmental psychologist, Henry Goddard. Henry Goddard, who is famous for many reasons. One of which is that he brought the IQ test from France to the United States. IQ being a topic that we'll touch on later in this course. Goddard believed that our fates were really sealed at the moment of conception. That once the sperm and the egg joined, our behavior was really determined. So unlike Galton, who believed in genetic influences on behavior, what Goddard and others like him believed was that our behavior was genetically determined. And that there was little that our parents, our teachers, our friends, our communities could do about that. The ideology of genetic determinism along with another development of Galton's time really led to the undermining Galton's goal. That other development was the Eugenics movement. Eugenics is the science devoted to trying to improve the human species by affecting who does and does not reproduce. Galton actually coined the term eugenics from Greek. Eu, well. Genics, born. And what Galton believed, and others like him believed at the time, is that eugenics, or what we were learning about genetics in the inheritance of behavior, could be used to address pressing social problems. Genetic determinism and the eugenics movement ultimately led to an undermining of early behavioral genetic research, as we will see in the next module of this lecture.
