The Interplay of Nature and Nurture in Human Development: A Systems View, Papers of Psychology

Download The Interplay of Nature and Nurture in Human Development: A Systems View and more Papers Psychology in PDF only on Docsity! 1 DEP 5058 Jessica Dahan 11/12/08 NATURE and NURTURE: APPLES and ORANGES In an effort to explain my position on the nature/nurture dichotomy without defeating the reader with pessimism, I will introduce my paper with a simple analogy. Apples and oranges—although both a fruit—their texture, purpose, flavor, physique, etc are one of a kind. People may prefer one over the other but they have never and will never merge into the same fruit. Similarly, nature and nurture— although both are important factors that contribute to a person’s development—they differ in composition, purpose, type/ size of effect on human development, occurrence, etc. While nurture is thought to affect development by the environment around the individual, nature is believed to influence the individual via biological and neurological pathways. These two factors that contribute to the development of a human being will rarely affect an individual in the same way as another. This is why I believe the long standing nature/nurture dichotomy will most likely never be resolved in psychology. Most people prefer to choose one standpoint which influences development and adhere to it. It is much too complicated to fluctuate between two viewpoints and assign one or the other as a reason for one’s developmental outcome. For example, a 28 year old woman gets diagnosed with high cholesterol. Based on the nature/nurture model, her diagnosis could be explained in various ways. She could have acquired high cholesterol through her diet (nurture) or this disease may have been passed down through her genes and the genes of her ancestors (nature). A blood test could answer this question for some people, but even then a combination of the two may be the reason for her diagnosis. Similarly, explanations for one’s health, personality, physical traits, and other characteristics differ between people. While some people may be more influenced by the environment they live in, others may be strongly impacted by the genes they have obtained from their ancestors. Still, some people are influenced by the interaction of the two. In my belief, the question of what factors influence which people when will never be fully answered. 2 The theory of probabilistic epigenesis which proposes the multifaceted contributions of both genes and the environment is, in my opinion, a good explanation for the variety in human development. This framework suggests that both factors work in conjunction with one another to create the individual and that the factors’ contributions are bidirectional. This means that genes influence the environment which in turn influences genes and the cycle goes on. (See Fig. 1) This framework answers the question “what influences development?” but has yet to answer the questions “why?” and “how?” In my opinion, these are the questions that must be clarified in order to solve the nature/nurture dichotomy and these have yet to be answered. Although I personally think the nature/nurture dichotomy will never be resolved, even with the idea of probabilistic epigenesis, it doesn’t answer all questions posed. I do believe however, that by adding in a third framework, this argument will be pacified. After careful consideration of various disciplines, I believe one distinct theme could possibly settle the disagreement between the two views and answer the questions these notions could not. Finding this framework was no easy task. This view was to be of greater influence to human development. This view was to solve the discrepancies found between various individuals and within one specific individual. It was to answer the questions that were posed by believers of the two views—biology and environment. It was to resolve the dilemmas that nature/nurture could not. This view has been around for many centuries and is one of the first paradigms to explain the way things are. Astoundingly enough, this view is religion. Although this ideology may seem farfetched to some scientists, it is the one explanation I can think of that will explain the variations that occur during human physical, genetic, psychological, hormonal, emotional, etc. development while at the same time keeping us so similar. Findings show that in some cases, genes determine development while in other cases, environment influences development. Since the beginning of time, religion has explained many issues—why things are the way they are? Who has made them that way? These questions when posed concerning the nature/nurture dilemma can easily be answered, perhaps a little too easily resolved. Monotheistic religions, believe 5 Maria Pienkowski Position Paper #2 November 14, 2008 There is no human nature or human nurture. We are constantly looking for explanations as to why things turn out the way they do over the course of the human lifespan. We have termed the general way a human being turns out human nature. The term human nurture has been used to define everything that goes on in the environment where the human is living. However, neither human nature nor human nurture explains anything about how and why individual physical and mental traits of individuals come to be. The proponents of the nature side of the nature/nurture dichotomy are of the view that phylogeny is the primary agent responsible for human development. They propose that the genes are the mechanisms that determine how a person turns out. Proponents of an exclusively phylogenic view see genes as unchanging and predetermined. Our genes determine how we will turn out before we even enter the world. Those on the nature side of the dichotomy view genes as fixed and unchanging, when in fact they are dynamic molecules that are part of an ever-dynamic developmental system. Evolutionary psychology, as a discipline, stems from the view that mechanisms are inherited through genes. An evolutionary psychologist purports that an organism encounters many obstacles in its environment. These obstacles, primarily obstacles in terms of survival and reproduction, cause some traits to be selected for and others to be selected against. Evolutionary psychology does not acknowledge that the environment, over the course of development, can influence phenotypic change. The other side of the nature/nurture dichotomy, the proponents of ontogeny, view human development as due largely in part to the environment. Those on the nature side of the dichotomy believe that the environment plays a primary role in the development of physical and mental traits in individuals. A change in an individual’s environment can entirely change their developmental trajectory irrespective of their genes. One example of an exclusively environmental view is the “refrigerator mom” hypothesis regarding autism, which attributed it to a genuine lack of maternal 6 warmth. This hypothesis has been dismissed, however, it illustrates the danger of attributing anything to only the environment. The nature/nurture dichotomy need not be resolved. It should be abandoned. In order for the dichotomy to be left behind, the field of psychology will have to undergo a massive restructuring. In the research world, psychology is often split up into different departments with little interaction. For example, those who work in cognitive psychology looking at areas of brain activation during a panic attack may have little interaction with those in clinical or developmental psychology looking at interventions for the same disorder. If the subfields could work together, they could immeasurably benefit one another. Beyond the world of research, the way psychology is practiced in the field must also be reconceived. Multidisciplinary teams should treat clients in order to fully realize every aspect of a particular disorder. A framework that could potentially reconceptualize how human development is studied is the cross-level dynamic biocultural coconstructive framework, proposed by Shu-Chen Li (2003). Li’s framework acknowledges not only the bidirectional relationship between the environment and genes. It integrates a temporal element into the relationship, by allowing for the interaction to occur on different time scales as some developmental changes occur in a matter of seconds and others occur over the course of a lifetime (e.g., moment-to-moment microgensis, life span ontogeny, and human phylogeny). The dynamic biocultural coconstructive framework also includes the multiple levels at which development occurs. By including multiple developmental levels (i.e., neurological, cognitive, behavioral, and sociocultural), the framework includes all subfields of psychology as well as many fields in biology and other sciences. It is also unique in that the framework acknowledges culture’s impact on all levels of development. The inclusion of human phylogeny, life span ontogeny, as well as microgenisis into a unifying framework helps provide a structure by which interdisciplinary research teams can simultaneously look at the development of the physical and mental traits of individuals. However, the most salient aspect of 7 the dynamic biocultural coconstructive framework is that it acknowledges the incredible amount of plasticity that exists on the many levels of human development whether it is genetic and neuronal plasticity, behavioral and cognitive plasticity or cultural and evolutionary plasticity. In order for the biocultural coconstructive framework or any other framework to rid psychology and other disciplines that study the development of physical and mental traits of individuals of the nature/nurture dichotomy, there must be a dramatic refocusing of ideology. A collective consciousness needs to develop among all that acknowledges the immense capacity for change that exists within the developmental system. This change is neither solely due to environmental influences nor fixed biological influences. Change is the result of the constant interplay between the two. Efforts to parcel out one agent as more influential than the other are misguided. Only by acknowledging the multi-level bidirectionality that exists between the biological makeup of human beings and the context in which we live can we move past the nature/nurture dichotomy. 10 References Gottlieb, G., Wahlsten, D., & Lickliter, R. (2006). The significance of biology for human development: A developmental psychobiological systems view. Inj: R. M. Lerner (Ed.), Handbook of Child Psychology, Vol. 1: Theoretical Models of Human Development (pp. 210-257). Wiley: New York. Heyes, C. (2003). Four routes to cognitive evolution. Psychological Review, 110, 713-727. Nature versus Nurture: Neck and Neck (2007). Psychology Today http://www.psychologytoday.com/articles/pto-19940501-000012.html retrieved 11/9/08 11 Irina Fredericks DEP 5058 Position Paper #2 Very few subjects in science have instigated such a heated debate as the nature/nurture dichotomy. Although most modern-day researchers came to an agreement that genetic and non-genetic (i.e., nature and nurture) factors cannot be meaningfully partitioned or assessed independently when accounting for developmental outcomes, the debate still rages on. Indeed, despite converging evidence from genetics, embryology, and developmental biology that development of any individual organism is a consequence of epigenetic, contingent, and dynamic interactions between genetic specification and environmental influence, some quarters of developmental psychology still attempt to define the causal power of internal versus external factors associated with development. However, such dualism with its excessive reductionism is no longer plausible in developmental science. It undermines the insights that from the moment of conception, both genetic inheritance and interactions with the environment are equally important factors in human development. Numerous research findings have established beyond doubt that no genetic material can become an organism without interacting with its particular environment and vice versa. Therefore, to analyze the contribution of one without the other is meaningless. No definitive statements can yet be made about why nature/nurture dichotomy has proven so resilient in spite of mounting empirical evidence pointing up its deficiencies. Whatever the reason might be, it is time to resolve this tired hangover from an earlier phase of science. One particular framework that could provide such resolution for the nature/nurture dichotomy and effectively take its place in explaining the development of the physical and mental traits of individuals is a dynamic systems (DS) view of development. What follows is a brief discussion of both the fundamental principles of this particular approach and its application in accounting for human and nonhuman psychobiological development. 12 According to the DS approach, the development of any individual organism is a self- organizing, probabilistic process, in which new structural and functional properties and competencies emerge and change as a consequence of bidirectional horizontal and vertical coactions among multiple, hierarchically organized levels of analysis. These include three functional organismic levels (i.e., genetic, neural, and behavioral) and three environmental levels (i.e., physical, social, and cultural). Further, in accounting for the development, the DS approach offers a constructive re- conceptualization of the notions of ‘genes’ and ‘environment.’ Namely, from this scientific perspective, ‘genes’ or genetic expression is determined by multiple influences from other levels of the developmental system, including molecular, cellular, physiological, and behavioral components. The ‘environment’ is not a simple concept either as it includes everything, ranging from the complex, multi-determined molecular interactions within and across individual cells to the ever-changing experiential history that include physical and living worlds, in which all life is embedded. Such redefinitions of genes and environment are likely to prove ultimate not only in resolving the nature/nurture paradigm but also in helping those who have yet to abandon the genetic determinism (which biologists now recognize as indefensible) and finally grasp the recent empirical breakthroughs in understanding human development. Instead of partition out living processes into genetic and environmental, the DS framework puts great emphasis upon the relationships between genes and environment, arguing that the cause of development is the interaction between these two components, not the components themselves. In fact, in the absence of appropriate environmental context, genes are impotent in the sense that they cannot cause development any more than stimulation in itself can cause development. Indeed, there is a growing body of literature demonstrating how epigenetic factors, including internal (e.g., neural and hormonal) and external (e.g., sensory) events, activate or inhibit gene expression during individual development. By conveying the interdependence of genes and environment in conjunction with the 15 development. Environmentalists countered with situations unexplainable through solely biological means. Clearly the environment plays a great role in development. There are examples of effects of environmental factors trickling down to affect even second generation offspring. Other experiments (like transplanting embryonic cells that would usually be on one part of the organism to another part before the cell “makes up its mind” as to what it is going to be) emphasize the importance of the environmental influence on biological outcome. However biology has something just as important to say. Although genes can be influenced by environment, they definitely have their own say in the plan. For biologists, genes provide a basic template from which development occurs, which then defines the parameters of behavior. However, even biologists are not aware of the extent those parameters can reach when left unfiltered by environment. In other words, we do not know how much the environment limits or motivates biology. At the moment we cannot know the restrictions imposed by environment or contrastingly the extent to which biology may be self -limiting. We know that organisms whose biological limits have been reached tend to die out; however we do not know the all the mechanisms and rationale behind this. Adding further complexity, Dr. Balan mentions that amidst this environment and biological interaction there still always remains a factor of randomness. This factor seems to permeate every aspect of development. You cannot predict or know anything about this factor except that it exists. The complexity furthered by this factor is incalculable. Dr. Timothy Johnston presents various models for the development of behavior that have been considered. Interestingly enough, as ideas progress and his models develop, both the environment (diet, temperature, gravity, other chemical and physical effects etc.) and biological factors (sense organs, nervous system, genetic activity) together play more significant roles in the effect on behavior. The complexity to be considered when assessing the causes of development and behavior is illustrated in his later models in his article Genes, Interactions, and the Development of Behavior. Realizing how 16 much more complex a task already considered complex is, it can even seem discouraging to ask questions and expect answers; consequently, categorizing developmental factors into one of two neat dichotomous classifications seems unfinished, oversimplified and plain erroneous. Over the last few decades we have advanced primarily two things that have brought into questions these conclusions made by the biologist or environmentalist: 1. we re-defined what is meant by the environment (to include internal and external environment) 2. we have found evidence of firm limitations on biology alone (genetic adaptations also made due to environmental changes). Epigenetics entered the picture and sent the whole nature/nurture debate for a spin. Although it would take some time for the science community to take hold of this new theory based on the evidence, for those involved in the research, any one side of the dichotomy alone seemed to provide an incomplete explanation for development. This has led us to conclude that strictly nature or strictly nurture premises are not able to provide accurate reasons, answers or predictions observable phenomena in development. I believe that the nature/nurture dichotomy in psychology can be resolved. The way to resolve the debate is to: 1. be open to the information provided by biology, neuroscience, genetics and other fields of science; and 2. be knowledgeable about evidence that proves nature versus nurture no longer makes sense - then drop the dichotomy altogether. It is not one or the other that plays a substantial role in development. It is only one with the other - one and the other - that can produce the outcomes that we witness. The study of the field is in its infancy. We are just beginning complex experiments based on the epigenetic mechanisms we only recently discovered. The important thing for psychologists to remember is that neither nature nor nurture alone will impact development. A framework like epigenetics paired with the knowledge from the other sciences helps us to resolve, rather remove, this false dichotomy and effectively helps us to more thoroughly and accurately begin to explain the extremely complex ongoing process of the development of individuals. 17 Zoeann Finzi-Smith November 13, 2008 Biological Basis for Behavior Development Position Paper 2 Aligning Fear of Complexity With Simplistic Thinking Undoubtedly one of the most controversial debates in psychology is the nature versus nurture dispute. In the beginning it was a simple argument on whether human development was based on biology (nature) or environment (nurture). One side of this debate is nature, which attempts to identify changes in humans as variations in gene frequency and attributing development to genetic make up, wherein it assumes that regardless of experience an individual’s development is predestined. In contrast to this is nurture, which believes that development is solely defined by an individual’s adaptation to environment with no influence being considered by genetic composition. For decades upon decades educated minds in the psychological field have dedicated time, theories, and careers to justifying one or the other side of this debate. From Darwin, who obviously was a supporter of the position nature, evident by his theory of evolution, justifying physical and behavioral attributes as product of those traits that have competed and been seen as successful thus passed on from a simpler form. To classical behaviorists like Pavlow, who favored nurture, as exhibited by his findings on classical conditioning. It is irrefutable that both sides propose good reasoning and rationale in their justification of thinking, yet it is in itself wrong headed. The very existence of this dichotomy is incorrect. It assumes that nature and nurture are separate entities or at least able to be identifiably distinct. This way of thinking is an extraordinarily 20 This plaguing fear of studying the unknown and walking blindly into a different way of thinking is what has held back the development of the understanding of human development since the emergence of this debate. We must not be afraid to pull back the sheet from over our eyes of the simplistic, under analyzed, unidirectional, hierarchical, wrongly headed question known for decades as nature versus nurture. You can never get to the root cause if you are asking questions which lead to answers which are delineated by pre-defined parameters. This framework of thinking creates way for even more ridiculous or meaningless questions, like assuming both are needed for development which one plays a bigger role. The best way I could think of resolving, or should I say dissolving this debate is by addressing those subcategories previously mentioned. By breaking it down piece by piece, scenario to scenario, we can best attempt to clearly see that in no situation does one play a bigger role than the other. 21 Tracey Garcia The nature/nurture debate has been raging between scientific communities since the discovery of the gene and DNA and continues into today. Fields within the scientific community are divided and disagree with how much variation of behavior can be attributed to genetics, to experience (i.e., prenatally and postnately), or to the combination of genes and environment. With new scientific advances allowing for more observation, testing, and discovery comes pressure from many people for the scientific community to end the debate and finally conclude what role genetics and experience have on human development. What many people fail to recognize about this debate is the various factors that impact this debate. These factors include, but are not limited to (and often interact), funding of research, the stability of development, acceptance of just so stories by the main stream and the scientific community, and many people’s wish that they will not have to be personally accountable for their actions (e.g., “its in my genes that is why I acted the way I did or do). In recent years a growing body of work has started to shed light on the role of genetics and environment, with the capacity to for once put the debate to rest. That work is termed dynamic systems theory, which is premised upon the idea that it is neither genetics nor environment alone that accounts for the variability found within in behavior, but instead is the interaction or co-action of genes and environmental factors working together that affect development. Thus, the nature/nurture dichotomy is false according to this view. Dynamic systems appears to be a way that the nature/nurture debate could be eliminated from psychology and other sciences, however, not everyone in the scientific community, let alone psychology, is ready to accept this theory. In my view, a dynamic system approach takes into account the complex, multilayered, and eloquent relationship between genes and the environment and could take the place of the nature/nurture debate in explaining development. Dynamic systems theory supposes that there is no master plan or blue print to development (i.e., no causal priority), but rather an organism is a self-organizing system that incorporates continuity and discontinuity (characterized by behavioral instability and stability) due to the organism’s initial 22 condition and its interactions with various environments (which includes constraints and opportunities) throughout its lifetime. This view of probabilistic epigenesis, while garnering attraction from the scientific community (including the psychological sciences), is often debated by the strict naturist or strict environmentalist and is still a minority viewpoint. Many within the scientific community do not want to accept this view of development. Theoretical reductionism has dominated and still abounds within psychology. The stability of development helps continue reductionism as many argue that if there is a self-organizing system then there should be more variability in phenotypic manifestations (e.g., the appearance of human physiology; progression of motor skills). They (those who oppose a more open systems approach) point out that children often look like someone within their family and may even have the same disposition. Humans have looked approximately the same for generations and often natural selection is used to explain the lack of phenotypic variation. However, natural selection cannot create; it must work with what is available. Often, in psychology (especially within the evolutionary psychology camp) and other sciences (e.g., biology), development is seen as unidirectional, whereby, an organism’s genes dictate the phenotypic outcome, and the most adaptive outcomes survive. What is ignored by a deterministic view point is the impact of the environment on genetics and evolution. An individual’s ontogeny may in fact impact the environment and the environmental changes can impact the individual’s ontogeny, thus creating a bi-dirctional relationship between the individual and the environment. Unfortunately, new research intiatives and funding are leaning more towards a biological detereministic view (e.g., the human genome project). Funding for studying development, especially normal development, is scarce and often must incorporate a more biological approach. The study of genes and the mapping of the genome (despite its unsuccessful linking to behavior) have had a gross impact on policy, funding, and the acceptance of genetic determinism by the mainstream. Policy makers impact funding, which in turn impacts the availability of monies for research, which then in turn impacts the amount of research generated on genetic determinism. As more research has been 25 dichotomy is also easier. Examining research questions from an integrative approach, which considers the bidirectionality of nature and nurture, may be overwhelming to some researchers, as well as would call for researchers to examine areas that they know little about or are not comfortable with. Therefore, researchers would need to be open-minded and have the desire to venture out of their fields and gain knowledge in other areas. Moreover, in order to conduct this type of research, researchers from different fields would need to be willing to work together on research questions. In my opinion, we are not yet at a point where most people are willing to take the time and effort to work together and share ideas. Additionally, the resolution of this dichotomy may mean that the way we have examined certain topics and the conclusions reached from these examinations may be incorrect. Therefore, the resolution of this dichotomy may mean that research topics which some individuals have been researching their entire lives may be flawed. Until researchers are willing to accept that lifelong studies that focused on one side of the dichotomy are flawed, the nature/nurture dichotomy will not be resolved. In addition, resolving this dichotomy will be very costly and will require numerous changes. Researchers will need to be trained and education will need to be reformed. Researchers will need to learn how to conduct their studies in a more integrative way, as well as become familiar with the findings of other fields and how they can integrate them into their studies. They will also need to learn how to work in a broader spectrum, instead of concentrating on a very narrow area. Education will also need to be reformed in order to allow this dichotomy to be resolved. Biology and the social sciences will need to be formatted to include an integrative approach, instead of focusing strictly on genes or environment. I do not believe that individuals are willing to put in the required effort and money to resolve this dichotomy. Until these fundamental changes are made, the nature/nurture dichotomy will not be resolved. 26 The dichotomy of nature/nurture will also not be resolved due to funding. Funding is a major source that affects the types of research studies that are conducted. Because funding is currently focused on the nature side of the dichotomy, a resolution is not possible. Until funding focuses on integrative approaches, this dichotomy will exist. However, funding is greatly influenced by the answers that appeal to most. Therefore, in light of the previous discussion, I am not hopeful that this will occur anytime soon. Although I do not feel that the nature/nurture dichotomy will be resolved, I believe that a dynamic systems approach could resolve the dichotomy and effectively take its place in accounting for the development of the physical and mental traits of individuals. The dynamic systems approach provides a complete view of development through its focus on the interaction of genes and the environment and the bidirectional relationship between the two, as well as the bidirectional relationship between structure and function. Development is not viewed as a linear process, but instead as the result of multiple underlying interactions over time. Thus, development is seen as being composed of multiple layers that interact throughout time. Furthermore, the dynamics systems approach centers around the idea of probabilistic epigenesis, in which there is no blue print for development; instead, it is the interactions among the different levels of nature and nurture over time that produce development. Moreover, development is viewed as a process of coaction between nature and nurture in which even behaviors that appear innate have been influenced in their prenatal and postnatal background by a system of influences called the developmental manifold concept. This scheme could effectively take the place in accounting for the development of physical and mental traits in the sense that it offers a more holistic and complete approach to development. It does not take one side or an additive approach, but instead focuses on the interactions between nature and nurture. In conclusion, in order to truly resolve this dichotomy, we would have to revolutionize the way we conduct research (i.e. how we approach our research questions, the factors we include in our 27 research, etc), as well as alter the way researchers think, provide training, and make significant changes to our education. Although a dynamic systems approach may resolve this dichotomy, the nature/nurture dichotomy will only be resolved if the scientific community is willing to make the required changes and the public is willing to support the outcomes of these changes. I do not feel that the majority of us are or will be prepared to make these changes. 30 rat pups suggests that exposure to brief early life stress, such as brief handling, alters the expression of genes. These examples support the idea that genes are not causal engines; rather, their expression depends on the co-action between biological (i.e. level of hormones) and environmental (e.g. circadian cycle, nutrition both prenatal and postnatal, temperature etc.) events. Furthermore, they dismantle reductionist accounts claiming that experience affects or triggers the expression of heritable traits. Insofar as genes and environments interpenetrate, we inherit genes mediated by environments and not pure genes. Dynamic systems theory illustrates that traits are 100% determined by genetics and 100% determined by genes, and thus provides an useful attempt to solve the nature/nurture debate. A relational framework aimed at solving the nature/nurture controversy has implications for the ways we conduct empirical inquiries. It suggests that inquires can be undertaken from the standpoint of nature and from the standpoint of nurture but only as long as it does not resort to theoretical reductionism and maintain a recognition that nature/nature is not “it” or the true explanation of mental and physical traits. Such inquires will also acknowledge that nature and nurture create a single whole and nature and nurture by no means they compete with each other. By broadening the level of analyses to reflect the bidirectional relationship between nature/nurture (e.g. developmental systems theory) a relational framework allows psychology to maintain its identity as a discipline versus becoming an offshoot of biology or culture. At the same time, by encouraging interdisciplinary research, a relational framework has the potential to better our understanding of how physical and mental traits develop over time. At the same time such an approach has the potential to elucidate some of the minimal ingredients that afford and constrain development, as well as the time (i.e. including historical time) and timing at which various factors exercise the greatest influence on the developing organism. While a relational view of development might reconcile the nature/nurture debate, this view is not without limitations. Conceptually, this is a logical framework, yet the intricacies underlying it might make its implementation difficult. Particularly, given the multiple internal and external influences within and between the various levels of development any factors that are found to impact 31 an individual’s development may not combine in similar ways or lead to similar outcomes in other individuals. While such diversity speaks to the plasticity of human development, it also limits the generalizability of findings. Furthermore, while not a limitation per se, any intervention programs or any changes in social policies adopted as a result of research undertaken from a developmental systems view need to reflect the individual differences implied by this framework. The first step towards reconciling the nature/nurture debate has been made with the rise of developmental systems approach and the recognition that genes and environments are interdependent and they mediate rather than directly affect physical and mental traits. Nevertheless, greater effort is required, including a systems theory that unifies the various explanations and emphases that exist within this approach (e.g. action theory, psychobiology theory etc.). Once a unified account of development is found and meaningful investigations are undertaken, chances are that the extant resistance will diminish. It will be our duty as developmentalists to further disseminate our findings with both the skeptics and the public in an effort to promote a comprehensive view of development. 32 Ashley Watson DEP 5058 Position Paper #2 I do not believe the nature/nurture dichotomy will ever be fully resolved in psychology, due to a number of factors. For one, I do not believe we have achieved a level of knowledge that would allow us to completely discourage the process of dichotomizing developmental causes, and I am not sure we will ever reach the level needed. Another reason stems from the fact that the knowledge we do have comes from many different sources, and in order to resolve this dichotomy one would have to be fluent in all of these various areas of knowledge or be able to come together with many other experts from these areas, to come up with common causal explanations for development. If we ever get to the point that we possess adequate knowledge about development and we can work together with experts in other areas, I believe psychologists will continue to dichotomize or at least continue to consider nature and nurture factors separately, placing more emphasis on one developmental factor or the other. This tendency to dichotomize is one that individuals are exposed to through culture and society long before choosing to enter into the field of psychology. Furthermore, species are continuously evolving and new discoveries about contributions to developmental outcomes continuously change the focus of psychologists. Developmental psychologists, amongst others, are always searching for the causes of developmental outcomes for different species, particularly humans. This is the reason for a debate such as the nature/nurture dichotomy. As information has been discovered and knowledge has formed, psychologists have been able to stand in one circle or the other, realizing that they do not have all the information needed to make that decision, but choosing to adopt the most convincing view available. Although many discoveries have possessed the potential to discount this dichotomizing of developmental factors, many individuals still choose to emphasize one factor over the other instead of looking at the possibility of an interaction between the two. It will take many more advances in the 35 Leah Warden Resolving the Nature vs. Nurture Conflict Throughout the years, there have been two conflicting frameworks in psychology: nature and nurture. It seems as though people have tended to believe that the development of individual traits is either an outcome of genetics or an outcome of one’s environment. However, it seems as though the current trend is slowly moving towards a more complex view, in which both genetics and the environment work together to produce outcomes. Since the early work of geneticists, the focus on development has tended to migrate towards the idea that an individual’s genes are responsible for physical and mental traits that he or she possesses. It was, and is still believed by many, that one’s traits and trajectory of development is predetermined before birth and that genes carry with them a specific blueprint that is manifested throughout the lifespan. On the other hand, there are those who believe that an individual is born with a “blank slate” and that all of his or her traits are acquired through personal experience and the interaction with the environment. With the advances in technology and the ability to study the inner workings of organisms at a molecular level, the main focus shifted even more towards exploring genes as the main source of development, although many still believed that the environment played the more significant role. The Human Genome Project was created to identify genes from a physical and functional standpoint. It was thought that this project would unlock many mysteries and uncover specific genes that produce specific outcomes, even with regards to mental traits and behaviors. However, it was discovered that there is a smaller number of genes than originally thought and that the development of traits and behaviors is much more complex and can not easily be explained by genes as dictating factor. Currently, we are at a hopeful point in time in which the nature/nurture dichotomy may be somewhat resolved. As more and more research is conducted, we are finding that the development of traits and behaviors cannot be explained by one or the other, but must be looked at together, with many 36 factors at play. The framework that seems to make the most sense at this time, with the available information we have, is that of probabilistic epigenesis. Probabilistic epigenesis rejects the idea that development is predetermined and that there only exists a unidirectional relationship between genes and behavior. It suggests that not only do the genes have an effect on the development of traits and the experiences (environment) of an individual, but that experience also has an effect on the genes and their expression. Furthermore, the probabilistic epigenesis framework stresses reciprocal influences within and between ALL levels of the developmental processes: genetic activity, neural activity, behavior, and the physical, social, and cultural influences of the external environment. When using this type of framework, one can assume that all behavior emerges from the bidirectional relationship between genes and the environment on many different levels. As mentioned, probabilistic epigenesist implies that the environment consists of not only the experiences that occur outside the individual, but also inside the organism at a molecular level. The original, less complex explanations for individual trait development and behavior sounded something like this: an individual is born with specific genes that predispose him or her to certain traits and behaviors. These outcomes will occur if certain environmental factors are encountered, thus activating the gene and producing the behavior. This type of thinking is that of a unidirectional relationship between the genes and environment that exist at one level. However, an example of a probabilistic epigenesis explanation that takes into account the bidirectional relationship, as well as the different levels of environment, would sound something like this: An individual is experiencing stress in his or her environment. As a result of the stress, his level of cortisol increases, changing the inner environment outside of the cells. This change then affects the environment inside the cells, thus affecting the gene and gene expression, which could possibly result in new behaviors or traits. This example shows how the reciprocal influences between the genes and the environment on many different levels are responsible for outcomes. 37 As it is becoming apparent that the environment plays a much more significant role than previously thought, other factors come into play as well when trying to determine why developmental outcomes occur. Not only do the interaction between existing genes and the experiences in the environment affect outcomes, but the timing of all experiences play a part as well. WHEN something occurs is just as important as WHAT occurs. Genes seem to have more of an indirect effect on behaviors and traits and are expressed and changed depending on what is going on in and outside the individual, as well as the timing of certain events. Any outcomes that occur depend on what is available in the environment and when. Furthermore, one cannot predict what all that will be available in the environment, thus leaving much of developmental outcomes up to chance. The probabilistic epigenesis framework seems to be more logical than either the unidirectional nature or nurture frameworks in light of many recent research findings. People are beginning to realize that the relationships between genetic activity and the environment are extremely more complex than originally thought and that the development of individual traits and behaviors cannot be explained by only nature or nurture explanations. It has given rise to a different type of thinking that allows us to look at development in a way in which we have determined that the structure and resources of the environment have a huge effect on how the inside of the organism organizes and produces outcomes. We can see that opportunities and constraints on developmental outcomes that the environment provides, along with the ongoing bidirectional relations with the genes, seems to be what is responsible for certain outcomes. Simply put, we are beginning to see the developmental PROCESSES are what are responsible for outcomes, rather than a single factor. Since we have discovered that the development of traits and behaviors is far more complex than ever imagined, we need ways in which to understand all the relationships and effects of the many factors at play. New disciplines, such as complexity science and systems biology, have emerged in order to use technology and mathematical models in attempts to understand and predict as much as is possible with the amount of information we have. We are only at a starting point with the realization 40 Western industrialized countries compared to non-industrialized countries where a more rounded body shape is preferred. In USA it was 8 times more common for white women to have anorexia than African-American women; however some may argue that this could be due to genetic make-up. More evidence for the nurture argument for anorexia has come from Serdula (1999) who found that society has become more fat and health conscious as the number of female dieters has increased from 14% in 1950 to 44 % in 1999 and in the number of male dieters has risen from 7% in 1950 to 29% in 1999. Another theory from the nature side is that Anorexia is due to low serotonin levels. Several studies have reported low levels of serotonin metabolites in patients with anorexia. So, we can conclude that in this particular example “Anorexia” is caused by a combination of both genetic and environmental influences. Psychology never will have a concrete and definitive response regarding the issue about nature/nurture dichotomy. Behavior and human growth and development in my opinion are a combination of both. Every aspect in the personality of an individual is a consequence of genetic expression and experiences acquired through lifetime. It is impossible to predict the behavior of somebody based on genetic information. It is important to analyze that that individual can react in different ways depending of the environment that he or she will be exposure. From my point of view in order to resolve the dichotomy and effectively take its place in accounting for the development of the physical and mental traits of individuals it is necessary to analyze different aspects and theories. 1. An understanding of development requires a deep knowledge not only of the sequence of the genome but of their regulated expression. A realistic view of gene activation is of pivotal importance since better than any other developmental process it manifest in detail the intricate interaction between genetic material and other developmental factors. 2. Especially in psychological research the concepts of “development” and “learning” need to be integrated instead of being studied in isolation. 41 3. It is important to understand the nature of inheritance that transcends the restriction to the genetic material as the sole hereditary unit. 4. Brain plasticity plays an important role in development, and behavior. This issue should be taking in consideration too. 5. Cultural issues and acculturation process should be studying and integrate as a part of social development and human behavior. 6. Many organisms developed under a pressure, so more investigations are required. Psychology, Biology, and Social Studies should be integrated in order to understand better the development of human behavior and the future in the next generations. Behavior: in particular human behavior, is a function of nature of nurture is a debate that will likely never be fully resolved. It is clear that there is a vital biological component. We know the structure of a person is genetically determined, and structured and functions are often strongly linked, indicating that genes influence behavioral tendencies. Nature could not be manifested as it is without some nurturing influence. Considering behavior from a genetic perspective would be too limited, if it were not recognized that it is rarely the case that a single gene is isolated as being the cause of behavior. Rather, it is much more often the case that several genes interact in producing the outward manifestation. During this course we have being reading different journals that talk about behavior and evolution; however a final and concrete point of view never is found, because it is a topic of controversy. The nature-nurture dichotomy is not reduce to the field of development biology and psychology but plays an important role in our conception of the process of evolution. One might even say that it was the very separation of nurture (germ line, genes) from nature (soma,environment, individual development) that cemented the exclusion of development biology from the Modern Synthesis of Evolution. The last two decades saw a growing interest in questions that the received view was not 42 able to address, such as questions about patterns and processes of phenotypic evolution, and the origin of evolutionary novelty and innovation. The last decade has witnessed enormous scientific advances in genomics, systems biology, social neuroscience, evolutionary, and ecological and developmental biology, phenotypic plasticity, niche construction, extragenetic inheritance, developmental systems theory). They challenge overly gene- centered/predeterministic and environmentalist explanations of behavior. Nature and nurture don’t interact as if they were separated entities, with nature as the a priori plan being separated from concrete living and nurture being the means for modifying nature’s plan through experience. 45 environments we are comfortable with because they are compatible with our own genetic predispositions. At the same time, our environments can influence the course of biological development Lastly, there is much plasticity in human development. Human beings are resilient organisms who display a remarkable capacity to change in response to experience. Early experiences rarely make or break us. There are opportunities throughout life to undo damage done by early traumas and to redirect young lives along better paths. In the end, I believe that the nature versus nurture debate is almost a false dichotomy because it is known that both forces play a role in human development. “Biology and environment are as inseparable as conjoined twins who share a common heart” (Diane Halpern, 1997). 46 Namitha Raju Position Paper # 2 Developmental research for the last many centuries has been based on the nature/nurture dichotomy. Nature represents genes that determinatively impact development. Nurture is interpreted by some as the physical, social and cultural environment that is outside of an individual while others interpret it as the non-genetic components, both of which that trigger the predetermined developmental instructions that are assumed to be within the gene. The nature/nurture dichotomy represents the conflict to find out if genes or the environment play a greater role in shaping ones physical and mental development. On the other hand, substantial research from the area of genetics, embryology and developmental biology, have been able to resolve this conflict and successfully explain development with a more epigenetic, contingent, and dynamic approach. Instead of looking exclusively at genes or exclusively at the environment, this alternative approach explains the development of physical and mental traits as a web of unique interactions among genes, the complex, multidetermined molecular interactions within and across individual cells, and the nature and sequence of the physical, biological and social environments through which an individual passes during development (Lewontin, 2000). This framework is known as (PE) Probabilistic Epigenesis. The self-organizing, probabilistic nature of the development process can be clearly illustrated with the example of embryonic stem cells which differentiate into different cell types based on the different environments they are exposed to. Further, Nijhout (1990) in her writings explained that the network or pattern of gene activation does not constitute a program, it is both the consequence of, and contributor to, development. Thus the theories of PE are able to debunk the argument for genetic predeterminism that had dominated developmental research for a long time. In spite of the ample evidence that show how organisms develop from a fully achieved epigenetic perspective, gene-centered explanations of behavior and cognition still prevail (Lickliter & 47 Honeycutt, 2003). When I searched for the key words, “nature and nurture” on the PsycINFO database, I found 7580 published works whereas the key word “probabilistic epigenesis” only brought up 173 published works. Even though this search is not a completely reliable analysis it serves to illustrate the approximate distribution of the amount of discussion in the research community on the nature/nurture dichotomy versus the PE framework. This contrast tells us a few things. Firstly, it points out that there are many more researchers who subscribe to the nature/nurture developmental framework than to the theory of PE. Secondly, we can assume that there is a higher probability of beginner researchers being exposed to this dichotomy for understanding development as compared to the theory of PE. Hence, it can be argued that even though the nature/nurture dichotomy has been resolved on scientific and intellectual grounds, it still appears to be unresolved for a large section of the research community who continue to adhere to the outdated theories. In my opinion, to bring closure to the nature/nurture dichotomy, the following are some of the initiatives that would need to be implemented: Creating awareness- Many people subscribe to nature or nurture when they look at development because these are the only theories they are exposed to. It is also possible that researchers who subscribe to the nature/nurture framework are unaware of the framework of PE or that they have not understood it well enough to appreciate its merit. Further, those who dismiss the PE framework feel confident to do so because they constitute the majority. If more people question the basis for a nature versus nurture approach, we can expect a shift in paradigm in understanding development. Therefore creating awareness about PE, which accounts for development in a more credible fashion is important. It can be done in the following ways: 50 Barbara M. Sorondo While my optimistic disposition makes me want to say that the nature/nurture dichotomy will one day be resolved, caution makes me hesitate to do so. Nonetheless, I can state with absolute conviction my belief that a resolution, if one ever arises, will certainly not come about in my lifetime. Most people nowadays, both within and without the field of psychology, acquiesce that both nature and nurture play a role in shaping the individual. There are a few, however, who stubbornly insist that it is either one or the other, and many, many more who give precedence to one side. To complicate matters, a belief in the dichotomy may not be blatant; it often tends to be insidious, as demonstrated by, for instance, Harper’s misguided if well-intentioned attempt to introduce development to the area of evolutionary psychology. The dichotomy has persisted this long partly due to the fact that our field is established on a mentoring system by which ideas, whether right or wrong, are passed on to future generations by the current one. While this system has its obvious benefits, it tends to produce future generations of researchers with a proclivity to modify and expand on the ideas of their antecedents, yet who seldom completely alter, much less cast aside or replace, these ideas. Thus, beliefs—including in the nature/nurture dichotomy—tend to be perpetuated over generations unless cataclysmic, field-changing events occurred. These events are rare, but fortunately not impossible. In the last century alone we witnessed two of these wide-scale shifts in thought in the United States: (1) the shift that led to the dominance of strict behaviorism and (2) the shift that led to its eventual downfall and the subsequent return to cognitive research. I think such a radical paradigm shift is necessary in order to eradicate the nature/nurture dichotomy, or at least to make substantial progress towards resolving it. One must not overlook the fact, however, that humans in general tend to tenaciously hold on to their beliefs. There are those who even today insist that the Earth is flat (the Flat Earth Society). Researchers are no exception to this rule and perhaps even, some have argued, more dogmatic than most, possibly due to an understandable hesitance to admit that the viewpoint serving as the basis for 51 their entire careers could be wrong. Thus, it seems unlikely to me that the radical and widespread shift in thought needed to abolish the nature/nurture dichotomy will occur in the near future. I think that instead established researchers in the field today will maintain their beliefs until the end of their careers. Consequently, I believe that our best hope for a resolution lies in future generations of researchers. If undergraduate—and even younger—students are taught that the nature/nurture dichotomy is futile while their minds are yet malleable, they can then carry this knowledge to their later years and careers and pass it on to succeeding generations of researchers. As most of us are aware, however, the dichotomy persists strongly in undergraduate education today. The challenge therefore lies in finding those among the established generation of researchers who are willing to introduce this idea to those just starting out in the field and in this manner gradually shift the perspective of psychology in order to revolutionize it. This is luckily a far easier, if lengthier, task than overthrowing the idea all at once. The media can be a great ally in this respect. Its elimination of the nature/nurture dichotomy as a viable point-of-view would be greatly beneficial and may even circumvent the formation of such a belief in the first place, as a child’s first exposure to science is usually through television and movies. However, as we have discussed in class, there is a great lag between research findings and their propagation in the media. One popular television show, for instance, recently featured a geneticist instructing his class on how humans use only 10% of their brains, a belief that was long ago discounted among the scientific community. Furthermore, we can scarcely expect agreement among the media and general public on a matter that is still hotly disputed among researchers, as is the dichotomy. If, however, the current scientific climate becomes conducive towards supplanting the dichotomy with another perspective, a credible alternative must be available, one that accounts for development better than the dichotomy does. I believe we already have such an alternative in developmental systems theory, which, as Rose phrased it, proposes that “organisms construct themselves, their brains and their behaviour [sic], out of the raw material provided by their genes and 52 the environmental context with which they interact” (p. 9). We have examined a variety of research over the course of the semester that supports why this theory provides a better picture of development than an additive “nature + nurture” point of view, including: (1) how the lateralization of the avian brain may depend on the chick’s orientation in the egg as an embryo, and not on genetically predetermined instructions, (2) how social isolation among humans has physiological effects that increase the risk of mortality, and (3) how covering a kitten’s eye alters the organization of its visual cortex. Developmental systems theory furthermore fills in the gaps left by the nature/nurture dichotomy. For example, asserting that genes contain a program for development triggered by environmental markers begs the question of how such few genes can account for such great complexity. As we have mentioned in class, humans, with language and self-awareness and consciousness, have fewer genes than a grain of rice. Developmental systems theory accounts for this supposed discrepancy by emphasizing the lack of any program contained within the genes. The number of genes an organism has then becomes irrelevant; it is their expression and their interaction with both the internal and external environment in which they exist that is essential to the development of an individual. Physical development is seemingly easier to explain than mental development, perhaps because it is reflected in tangible evidence, whereas mental processes remain elusively invisible. Here again developmental systems theory triumphs over the dichotomy. Language acquisition devices (“nature”) and behavioral shaping (“nurture”) approaches to language, for instance, fail to adequately account for exceptions such as Genie and Victor, in the case of the former, and the near-universality of language, in the case of the latter. However, we humans (almost) all share certain commonalities: we are exposed to language from our earliest moments in a social culture that relies heavily on it, we are surrounded by people who communicate with us from birth, and we share the general structure of a brain and a body. These and other factors interact bidirectionally to result in language or not, depending on the circumstances, accounting for both normalcy and outliers.