Lec 1 Introduction to Developmental Psychology

Hi, good morning. Um, this is going to be our first session for our course, Developmental Psychology. So, what will happen is, uh, for this video, we will have a discussion about, um, the introduction of Developmental Psychology, plus, um, the importance of the debate between nature versus nurture. So, let me share my screen so we can start.

Okay, so for this one, this will cover two, or table of specification one and three, and it's the introduction to developmental psychology. Okay, sorry about that.

Okay, so I would like to start it with a quote from Jean Piaget in Genetic Epistemology. As in developmental psychology too, there's never an absolute beginning. So, when we study developmental psychology, we, we always start with prenatal development, but we need to understand that there's no absolute beginning of a human person, of a human being. So, we will always have a sense of continuance when it comes to studying, um, you know, a human being from conception to death and dying.

So, when we ask the question, "What is developmental psychology?" one of the common answers would be is that it's a branch of psychology that tries to understand how a child grows and develops, and how the role of the family and schooling can impact on this. So, it will always be about the development of a child from conception to, um, you know, to adolescence. And it's also about how a child develops in all aspects or in all domains of his or her life. So, let's see, social development, cognitive, physical, moral, and so on and so forth. It looks at how our behavior, thinking patterns, emotions, and personalities begin and change from birth to adulthood. So, it tries to understand how a person develops, you know, our emotions, how a person develops our person, uh, our personality, and then how we, how, how our thinking matures, how our cognitive functioning matures into something that is, um, acceptable in our society. So, that's usually from birth to adulthood.

Now, um, what is important in developmental psychology is that it understands human growth and development across the lifespan, across the, uh, the development of a person from birth to, uh, what do you call it, from birth to death and dying. And according to the American Psychological Association, developmental psychologists usually focus on human growth and changes across the lifespan, which includes physical, cognitive, social, intellectual, perceptual, personality, and emotional growth. So, if your plan is to become a developmental psychologist, your, uh, research focus will be about the, the phenomena that happen, or the phenomena that happen, um, across a lifespan. Let's say, what usually happens when a person is already emerging adulthood, or when a person is in puberty, or let's say, um, what happens to the cognitive development of a person when that person is around 40 years old and then was diagnosed with an early onset Alzheimer's, or let's say, uh, a person who's, uh, uh, what do you call that, when whose person, sorry, whose development is growing up to be in a not-so-acceptable domain or an acceptable context? Let's say, a victim of abuse or a victim of teenage pregnancy. So, what are those, uh, how, how are those specific phenomena, uh, influence the usual human growth and changes? So, it can be something specific like that, or something that is unusual like that, or it can be something that we study across, you know, something normal that we study across the lifespan.

And then, um, there are periods of development. You have the prenatal period, infancy, you have early childhood, middle and late childhood, adolescence, early adulthood, middle adulthood, and then late adulthood. So, as we go through these periods of development, changes or development happens in the cognitive processes, um, biological processes, and social-emotional processes. Um, changes and development happen in these domains. So, what happens to the brain of a person physically and cognitively as he or she gets older? Or what happens to the physical body of a person as this person gets older as well? Same thing with, um, social-emotional, uh, changes.

Okay, so the key concepts in developmental psychology are usually several domains, but the most common ones are the physical, the cognitive, social, and emotional. When we discuss the different theories of, uh, development, as well as different developmental stages, we will focus on these domains. It's cognitive, physical, social, and emotional. And, um, as we go along these, uh, theories and stages, we are grounded by the developmental principles that we have in developmental psychology. So, we have these principles that we continuously believe because we know that a human being experiences, uh, these principles.

One is that development is lifelong. So, when you say development is lifelong, no age period should dominate development. The common belief before is that, uh, development of a person, think, you know, it, it peaks and it's rampant when it comes to, uh, prenatal development to adolescence. But now, in our time today, we understand that development, development is like things, or, you know, domains are still developing even during early adulthood to old age. There are still things to learn, there are still things that are being developed during death and dying. Our culture, um, our impact, the impact of death, the impact of death and dying can still influence a human being. So, it's lifelong. The moment that you are conceived to the moment that you die, things are developing. So, researchers increasingly study the experiences and psychological orientations of adults at different points in their lives. So, we understand in developmental psychology, we understand that, uh, different psychological orientations that we need to understand at different points of our life. So, there are different ways that we look at, um, certain concepts like maturity or sexuality. So, we have different experiences and orientations when it comes to those at different points of our lives. So, lifelong development means that development is not completed in infancy or childhood. At any specific age, it encompasses the entire lifespan from conception to death. Things are still developing. There are still, um, aspects of our lives that are still developing, even during death and dying. So, each developmental stage is important. So, because we need to learn, we need to conduct research on the different, uh, developmental stages.

And then we understand that development is multi-dimensional. So, in every developmental stage, there are different dimensions that are developing. So, we have the biological development, our physical growth. We have the cognitive maturity that is happening. We have social-emotional, um, dimensions that are happening as well. Our personality is always changing. It's always developing from the moment that we were able to develop it to the moment that we die. It's always changing. It's always developing. So, even within a dimension, there are so many components that are happening. So, let's say, cognitive development, in that dimension alone, my goodness. So, our problem-solving skills are being developed, our, uh, decision-making, our memory, our schemas, all of these concepts, they're being developed as we get older. So, social-emotional, we have, uh, we need to understand our, our idea of empathy and how it develops, how we interact with other people, how we develop leadership, leadership, how we develop leadership, how we get along with other people. So, and development is multi-dimensional. It happens in all aspects of development. And then in one aspect of development, other components are still being developed. So, it's a dynamic interaction of factors like physical, emotional, and psychosocial development.

Like, for example, for example, my son, my son is 11 years old. So, he's in puberty. For, um, but, but his actions or and decisions, shifts, they shift from, you know, from middle childhood to puberty level of decisions, you know, of emotions and everything. So, let's say, for example, last Sunday, last Sunday, he was dressed like the way he wants to be dressed. He was wearing his color shirt, he was wearing his favorite, sorry, pants and shoes, and then he's acting like an adolescent already. So, so there, and then, um, at 11, there's this one tooth that needs to come out or that needs to be replaced. And then, luckily, last Sunday, that tooth came out already. And then he said, "Mom, we need to keep that. It's a issue." Let's throw it in the trash can. But he said, "You need to keep it, um, because that's my tooth." I did not ask for a reason. So, I just kept it and I put it in my bag, put in the tissue, kept it in my bag. It was around 11:30. We were already trying to sleep. And then suddenly, he was knocking at our door, bedroom door, and then he said, "Mom, where's my tooth?" I think it's still my, oh, I needed for the tooth fairy. I was looking at him like that. That in my mind, I was saying, "My 11-year-old son is still, uh, still believes in the tooth fairy." And then I was, "Okay, here, here's the, here's the, here's the tooth." And then he went, he went back to his room. And then I don't know what happened. Then I told my husband, I remembered that I never revealed about that about good fairies because, um, most of his teeth fell off or, you know, it was replaced around seven or eight. Then after that, it slipped our minds. You know, we did not, we did not reveal anything to him anymore. But then two nights ago, that's what he said, "I need to give this tooth." Should I still give him 100 pesos for the tooth fairy? I guess so. So, uh, when he was asleep, my husband, when my son was already asleep, he went to the room of my husband, sorry, when my son was already asleep, my husband went to his room and then he put the 100 in at his headboard or on his headboard. And then we wake him up usually at 5:00 AM to prepare for school. His door entered his room, saw the 100, and usually it takes around 10 to 15 minutes to wake him up. But during that day, on Monday, when I woke him, and then he, for the, sorry. And then, um, so he looked for his money. He was happy that we have his money. And then I asked him, "What do you plan to do with your money?" So, and then he said, "I plan to buy taho, my school taho." And what, right now, he's not, U, sorry, right now his lunch is coming from the house. So, whenever we give him money from time to time, he always buys taho or, you know, some drinks in his cafeteria. So, and then when he dressed up, when he, when he started dressing up for his school, here comes the teenager again, all serious and all, all teenager in on his way to school. So, the shifting. So, I think this is an example of a multi-dimensional development. So, it shifts. So, physically, he's starting to look like a teenager, but there are still parts of his body that I believe are still, um, middle, in middle childhood. Emotionally, most, his shifts, his emotional development shifts from being a teenager, something so moody, sometimes he just wants to be quiet, but then there are times that, you know, his processing is still for a child, for a middle child, middle childhood eras. So, it's multi-dimensional. So, those different aspects, different developmental levels, they interact with each other, and that unique interaction makes a person unique, makes a person who he or she is during that particular time.

And development is also, uh, multidirectional. So, throughout life, some dimensions or components of some dimensions or components of a dimension expand or other shrink. So, some aspects of our, uh, development are expanding, some are shrinking. So, as we get older, our eyesight gets poorer. For me, as I get older, I notice that it's in my genes that I will have more white hair. So, the more color, the more instances or the more, uh, the higher the frequency of color hair. Because right here, so some dimensions of my physical development, or some aspects of my physical development, strength or deteriorates, while others are expanding. I, I would like to believe that as we get older, as we get, uh, more exposed to the to the experiences that we have in the world, I, I would like to believe that we also develop wisdom. So, humans change in many directions. We may show gains in some areas of development, other, while some, while showing losses in other areas. So, every change, whether it is finishing high school, getting married, or becoming a parent, involves both growth and loss. So, as we expand our cognitive maturity, as we expand or as we get more cognitively, uh, cognitively mature, some physical aspects are, development is also deteriorating. So, physical, uh, physical deterioration.

Then, um, development is plastic. So, when we say this principle, it means that the characteristics are valuable or changeable. We will always have the capacity for change. So, a human being is always capable of change. So, for example, can you still improve your intellectual skills when you're in your 70s or 80s, or might these intellectual skills be fixed by the time you are in your 30s, so that further improvement is impossible? So, I believe that, um, change, you know, change will always happen in our lives. So, human beings will always adapt to that change. It will always, uh, it will always make our lives interesting, or it will always make our lives more, um, sometimes more challenging when it comes to living, living our life. So, let's say, for example, because I'm in my mid-40s, I'm, I'm 43, turning 44 this year, and then my husband, always say, my husband is turning 46 this year. Then I refuse to, I refuse to, I always tell him, I refuse to label myself as "matanda" because at this time, at this day, being 43 or being 44 or 46 is no longer being "matanda." Maybe that was the way that they think before, around the 1980s or 1990s. But, you know, with science, with the development in science that are happening, with the changes that are happening, with different research, uh, articles coming out about aging and how, how life's proximity keeps on, uh, getting older, age, common age that people die is around 70, 65 to 70, it's around 78 or 80. So, I refuse to label myself. I always say that, I, I refuse to label myself as "matanda" because there are still so many things that I can do, and I believe that I can do them because, because I'm still young. I consider myself as still young. My, my husband will always tease me. That's my belief. So, even though I'm in my forties, I know that, you know, a person who's in his or her prime can still do a lot of things. The career can still start. You can still shift your career or change your career. And it's just, you know, the labeling that sometimes, so, but development is plastic. There are still changes that are happening in our lives. Our characteristics are always changeable, and it's in our, uh, and it, it's in our psyche that we always adapt and change.

And then development is also multidisciplinary. Developmental science. So, in order to fully understand the development of a person, we need to look at it in different aspects, in different disciplines. What happened to, uh, what's happening to the society as a person is changing? So, right now, we are in an era where in, um, you know, impeachment is happening, wherein our vice president might be impeached, or, you know, breakups of breakups and fights of actors, actresses, and celebrities are, you know, our, they're like our entertainment nowadays. And then the way that we find out about this breakups are through our social media channels like TikTok, Facebook, and all those things. Or the article that I was reading, "Kina" was the breakup of, um, Andi Eigenmann and her boyfriend, Siargao something, and her boyfriend. So, it's so popular in TikTok already, so popular in Facebook already. And then another issue, pala, that is coming out is the, the breakup of, uh, Samuel L. Jackson, Puno, G. So, those things, those social phenomena, as in significant as they may be, they, they influence our lives. They influence our, you know, our everyday lives. So, because for me, in our household, pala, last night while we were having dinner, my husband and I were talking about the breakup of Andi Eigenmann and Siargao. And then we were talking about beforehand. So, we didn't know that because it was only now that this couple was in our consciousness. First, first wife. And then my husband said, "Google." And then I Googled it, and it turned out he's only 32 years old. So, could change perspective there. So, it's part of our conversation in the house, in dinner time. So, those things, the, the things that are happening around us, that's sociology, that's anthropology, the history of the, of, uh, our society. So, it's multidisciplinary. It influences how our development, uh, as a person, uh, is, you know, is happening. So, it has an influence on us. And then I also would like to believe that the neuroscience and then, you know, biological psychology also has a great impact in developmental psychology. Now, we believe that if a person has depression, if a person has schizophrenia, chances are it's because that there's a chemical imbalance in their brains. We need to, um, we need to balance out the chemical imbalance in their brain so that the symptoms will cease, or the symptoms will, uh, decrease. So, we have so many interests, and it's multidisciplinary because, let's say, if you want to study about child depression, if you want to study about, uh, child anxiety, you cannot ignore the biological aspect of how depression can influence a developing mind, you know, a, a mind of a teenager, or a mind of, uh, you know, mind of a child. So, it's multidisciplinary. We work better, we discover more when we work with other disciplines. So, in psychology, we usually work with sociology, um, sociologists, and with the medical doctors in the medical field. But we understand the importance of, um, you know, multidisciplinary research.

And development is contextual. So, all development occurs within a context or setting. Contexts include families, schools, peer groups, churches, cities, neighborhoods, university laboratories, etcetera, etcetera. So, each of our contexts is influenced by our historical, economic, and social and cultural factors. Again, or just imagine, uh, for people who have children here in our class, when I discuss this, I always think of my son. So, my son is growing up in my 11-year-old son is growing up in a society where if you're a vice president, can be impeached, "poo" is a common word that is happening. "W hashtag" is part of, uh, their school year. Cyberbullying is rampant in his school and in other schools. Ano, um, you know, the son of a dictator is now our president. And then he's developing in a world where in political dynasty is a, is, you know, is the norm right now. And there are other cultural factors like, is influenced by his hobbies, hobbies, and his interests, which are unfortunately, it is so Western, Western influence. So, he loves Pokemon, he loves Roblox, he watches. Right now, he's actually very into, um, Greek mythology that was turned into TikTok videos. "H," are you sure that's safe for you? Because most often than not, he knows how to filter, he knows his limitation. So, are you sure that's safe for you? TikTok videos, Greek, you know, Greek mythology. He thinks it, it gives him the history of heroes, Achilles, Odysseus. He knows, he knows his stuff already when he, uh, when we have our conversations. Most often than not, now, during the past month, it's about Greek mythology. And he kept asking, he kept teasing me because I said, when I was in high school, I loved Greek mythology because it's part of our curriculum before. So, it was one of my favorite subjects. But I can't remember any of it right, or anymore. But what I do remember is that, you know, the love of reading the Greek mythology book. And then he said, and then I asked him, "Do you want me to buy you that book?" You know, a Greek mythology book. And then he said, "Never mind, Mom. I can, I can find it in YouTube or I can find it in TikTok." So, those factors. So, it's contextual. The way I learned Greek mythology before was so different with the way that he is learning Greek mythology right now. So, I was exposed to Greek mythology when I was 15, 16. But because of social media, my son was exposed to Greek mythology when he is only 11. It's contextual. The way that we discipline our children before is so different with the way that we are disciplining, we are still disciplining our children right now. So, when you try to understand the development of a person, we always need to consider the context around that person, what's happening to the to the country, to his community, his school at that particular moment. Okay, so it's context.

And then there are things that are happening in a world that is normative, uh, in a person's life, pala, rather, that is normative age-graded influences. So, these are factors that are correlated to our chronological age, such as, you know, and it's very, uh, we can expect that these things will happen. So, it can be puberty, it can be the, you know, the loss of a tooth for my son, or it could be menopause, or for me, it could be very menopause. So, these are age-based, uh, social practices that happen because of biological age or some environmental factors. And then there are also some normative history-graded influences that happen because of a certain environmental and cultural context. So, as I've said, these are the things that happen in our country as my son is growing up. Let's say, and, you know, the influence of social media, yeah, the influence of, um, you know, giving importance to privacy, giving importance of not posting a lot in social media. So, it's specific, there's a specific time period. And then you have the non-normative life events, the unusual occurrences that have a major impact on the individual's life. So, let's say, um, if the parent separated, what will be the effect on the child? Or if there's a sudden, then early death of a parent, what's the effect to the child as well?

Okay, so another one is that development involves growth, maintenance, and regulation of costs. So, because we are, if there's something constant in our lives, it's change. And in change, we have gains and losses throughout our lives. So, usually, our gains, our development are obvious early in life, but losses are more obvious later. So, we lose our eyesight, the clarity of our eyesight. For my husband, it's his sense of hearing. Um, what else? My white hair keeps on growing, keeps on multiplying. So, we have gains, yet we also have losses. So, adaptation to change involves three global processes. We have growth, we have understandings, we have wisdom and everything. But we also have regulation of laws. We have a lower level of functioning. We, we lose some aspects of our physical agility. And we also have resilience. We have ways to continue or to restore functioning after loss. So, uh, we have ways to make sure that our body will not be greatly influenced by this process. So, success means maximizing gains and minimizing losses.

So, we have this standard, um, debate. The most common debate in in developmental psychology is nature versus nurture. Which is more important? Nature, uh, sorry, yeah, nature, our our genes, our biological aspect, or nurture, the way that we were brought up by the environment? So, according to Watson, he's a behavioral psychologist. "Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in, and I'll guarantee to take anyone at random and train him to become any type of specialist I might select. I can train him to be a doctor, a lawyer, an artist, regardless of his talents, pension, tendencies, abilities, vocations, and race of his ancestors." So, he believed in the power of nurture, of the environment, and how it can influence the development of a person. So, he said, like, you know, a person is like a blank slate. A person is like a tabula rasa. We, in it's the environment, it's the experiences that makes a person who he or she is.

And then, uh, the debate between nature and nurture is that, according to nature, our genetics determine our behavior. Our personality traits and abilities are in our nurture. Nature, sorry. So, when we were born, we have this, uh, intelligence level already, an IQ already that we can nurture as we get older, but it's there already. Our temperament is already with us when we were born. So, that's also nature. In nurture, it believes that our environment, our upbringing, and life experiences are the ones that determine our behavior. Our context around us, uh, the world around us, our experiences are the ones, uh, are the ones that give us who we are and that shape us as who we are today.

So, important is it nature or is it nurture? In nature, the basic tenet of this debate is centered on whether the child is born with capacities and abilities that develop naturally over time, regardless of upbringing. So, regardless of who we are, of what our environment is, pala, regardless of where we grow up, our genes is the one that makes us who we are today. So, that's according to nature. But according to nurture, um, our, or the child's social interaction in society in order to shape them. The context where we are growing up with, the environment where we are growing up with, that is more important, according to them.

So, John Locke, John Locke, he was, uh, he was one of the philosophers that psychologists usually rely on, or, you know, that has a history of psychology, pala. So, he said that, uh, he was an empiricist. He believed in the scientific method of observation and experimentation. He wrote of the tabula rasa. So, he said that a child, when that child was born, is like a black canvas. So, it's only through social interaction that the child learns to speak, learns emotions and morals, learns to react, learns to exist within the society. So, he believes that for a person, for a child to be who he or she is, there needs to be an interaction with the society because that is where that the child will learn how to speak, how to handle emotions, how to handle their morals, and everything. So, John Locke says that, I, you know, children are like black canvases.

John Jacques Rousseau, I hope I'm pronouncing it right. Rousseau agreed with Locke and that social norms and values were a strong factor in creating a person through experience and contact with others. But he saw the role of society from a different perspective and coined the term "the noble savage" to describe the innocent, good child becomes corrupted by society. And all the, and so for the, so society was an insincere and crooked place that was harmful to children who, by sheer lack of birth, they considered were almost our nature. So, negative view philosopher. He believed that, uh, it's the society who brings the, the negative aspects of a human being.

But you have this study, the Minnesota Twin Study. So, this, this is the original study. "Pedigree" there's a title here, "Kasohal." So, this one was made by, again, I hope I'm pronouncing it right, Bouchard. So, according to this psychologist, um, he believes in genes. So, he said that the outcome of the Minnesota Twin Study provided evidence of slightly different outcomes for the twins, but mostly of considerable similarities in the temperaments, educational and career choices, and even relationship patterns in the separated twins. So, Bouchard argued that this study provided evidence for the importance of genetics in determining behavior. And this was in 1990 to confirm, uh, his initial finding. So, he said that at the study, participants of this study were twins that were separated. And then the results of this study says, no matter where you came, where you end up with, genes will always matter because, well, in this study, it provided evidence the importance of genes when it comes to, uh, temperaments, educational choices, relationship patterns, because even though these twins were separated, the temperaments remained the same, career choices remained the same, and even relationship patterns. That's why there's a picture because both of them became astronauts.

So, how do we tackle the nature-nurture continuum? Now, in the 21st century, most psychologists have decided that neither nature nor nurture on its own is likely to be fully accountable for the development of society. Continuum. It's not, it's no longer a debate between which is better, nature or nurture. It's more on. So, majority of psychologists are located somewhere in the middle of these two extremes. So, we believe that there, the two aspects have, I know, have equal importance, the nature and the nurture. And, um, if the child is in the period of his life that nurture is more important, then during that time, nature is the dominant force. But if, let's say, another aspect of the person's life, nature is more, nature is more influential, the nature is a dominant force.

Okay, so in approaches in psychology, if you believe in nurture, the importance of environment, the importance of the context, then you are more of humanism and behaviorism. But if you believe in the importance of genes, the importance of, um, biology that are in the biological psychology aspect or in psychoanalysis, the one in the middle, doubt is cognitive psychology. We believe in the importance of the human brain, but we know how social interaction can actually influence the, the growth and development.

So, so here, let us discuss now the importance of early experiences. So, according to some psychoanalysts or some attachment theorists, there's a big importance when it comes to the, uh, early attachments. So, so what will our adult love relationships be like if we had a close relationship to our mothers as children? So, usually, the questions are, how would our adult relationships be different if we have been raised without a mother? Perhaps if we have been raised in institutional care? How important is that early relationship between a mother and her child in shaping who we are as adults? And equally important, can the effects of that early relationship be changed once we reach adulthood? So, the relationship that you had with your mother can greatly influence, um, your, uh, later development in life.

So, sorry, one of the key factors in the argument about the importance of early experiences is whether we continue to develop socially, emotionally, and cognitively into adulthood, or whether we are essentially childhood. So, the debate is, is it important, ba, our early experiences? Because if they are, whatever experiences that we had when we were young, whatever relationship we had with the primary caregiver, it will shape the lives that we have in the future. It will shape how we build relationships, how we maintain that relationship, and the kind of life that we will have in the future. Thus, early experiences in developmental psychology are considered important in molding who we are as children, in helping us to understand who we are as adults. But we also know how important, how critical the experiences of the early years. We understand the importance of context that even though we have this early life experiences, the context of where we are right now can still be very influential in how we deal with, you know, our everyday lives. Okay, so there. But, you know, developmental psychology always be in the importance of early experiences.

So, let me, uh, show this video, the importance of epigenetics and how the balance between nature and nurture is important. So, show that video now. Oh, sorry. Uh, and look for in YouTube. Y. I know the [Music] meet Lucky Lyle and Troubled Tim. Now, you might think they look a lot alike. That's because they're identical twins. But imagine them being raised in completely different environments. As adults, they turn out very differently. Lucky Lyle is a model citizen. He goes to work, pays his taxes, treats others well, and gets an education. Troubled Tim is on a different path. He robs banks, doesn't pay taxes, and gets his first prison sentence at the same time as Lyle gets his diploma. Their genes are identical, so it must be their separate environments that have made them so different, right? Well, there's more to it than that. Much more. We need to rewind a bit in time. You see, one of the great questions of humanity is, what makes us us? Huh? Early explanations had a hint of the supernatural about them. As the centuries whizzed by, science emerged and fought a tough battle to gain credibility. Eventually, social science emerged with a popular theory that our environment is what makes us us. Let's call this nurture. Undaunted, the biological sciences presented another theory: genes. An unchangeable blueprint in you from birth decides everything. Let's call this one nature. So, are we a product of our genes or of our environment? The battle raged on. Observations in a newer field of study suggest that both are partly right. This field is called epigenetics. It means "above genetics" and has to do with how nature and nurture interact. At the heart of this discussion is one simple question asked by researcher Michael Meaney: What makes a good rat mama? Well, for rat mothers, nothing says love and care like some nice vigorous licking. The higher the number of licks, the more love, and the better the mama. With this in mind, the researchers compared two groups of rat mothers: one that licked their babies a lot, and another that didn't. They found that when babies grew up, they carried their mama's behavior with them and passed it on to the next generation, and the next one, and so on. But could it simply be that this particular group of rats was genetically predisposed to produce caring mothers? Well, to test this, the researchers took newborn babies from low-licking mothers and fostered them with high-licking mothers, and vice versa. It turns out that if the mother is a high licker, the rat baby becomes a high licker too, regardless of whether it's genetically related to her or not. So, genes really don't have anything to do with it then? In true scientific fashion, the researchers dove right into the brains of these rats to see what, if anything, was different in the brains of the babies of high-licking versus low-licking mothers. When they looked at genes that possibly play a role in motherly care, they found crucial differences. Newborn rat babies have clusters of molecules called methyl groups attached to these genes. These methyl groups silenced a gene, effectively switching it off. The researchers discovered that while the methyl groups in rats from low-licking mothers were still attached, in the rats from high-licking mothers, these methyl groups had disappeared. This was also true for the rats that had been adopted by high-licking rat mothers. The care these rats received from their mothers actually physically altered their genetic expression. Now, that's all fine and good for rats, but what about people? Well, the same is true for Lucky Lyle and Troubled Tim, and for you and me. The genes you're born with are the genes you've got, but lifestyle and environmental influences, such as nutrition, exercise, smoking, stress, and love, greatly affect your biology. These changes can actually be observed at the DNA level. The bright side is that epigenetic changes happen throughout our lives, and our choices can make real differences in how we develop as human beings.

Okay, so show and sorry. So, here we see the continuum between the importance of nature and nurture. So, instead of defending, um, extreme nativist or nurturist views, most psychological researchers are now interested in investigating how nature and nurture interact in a host of qualitatively different ways. So, there are ways that, you know, nature can influence how we interact in the environment, and how our nurture, how our life experiences can actually enhance the genes that we are born with. So, in the nature versus, for example, the nature versus nurture of intelligence, intelligence is highly heritable, with about 50% of variance in IQ attributed to genetic factors. But environmental influences, such as access to quality education and stimulating environments, also significantly impact, uh, intelligence. It is how we, let's say, if you're highly intelligent, this is how you use your intelligence. It is how you manage the experiences that you had and to, uh, you know, to adapt to the environment that you can use your intelligence. So, there, so intelligence results from complex interplay between genes and environment over development.

Okay, so there. And the last is that when it comes to child development, um, we believe that humans are born with an innate capacity for language, known as grammar, uh, suggesting that genetics play a significant role in language development. But we believe that the environmental reinforcement and learning in language acquisition is even more important. Okay, so the way that a child learns, the things that you expose them with can help a child develop language. So, there, if you have time, just kindly go to the site because it will direct you to, you know, an article about nature versus nurture. So, there.

So, that ends our first lecture about developmental principles, about, um, you know, development of principles and the importance of the nature versus nurture debate. Our next lecture will be about, um, research ethics, specifically in developmental psychology, as well as the different kinds of research used by developmental psychologists. And we end here. So, thank you for listening. Bye.