Apr 2, 2018 12:05 AM
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Develop a chart or diagram that will illustrate how prenatal development is influenced by environmental or genetic factors. Creativity is strongly suggested. There is no requirement for APA format in this assignment. There is no requirement of references for this assignment.
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Nature and Nurture: Genetic and Environmental Foundations of Child Development
Child development is impacted by both genetic or inherited factors and environmental factors. Genetic factors are inherited from both parents at the time of conception, but can be the result of different types of gene interactions. Environmental factors impact different ways families function and children develop. Environmental factors include the ecological systems that may alter family function, socio-economic status and cultural values and public policy.
TOPICS COVERED WILL INCLUDE:
· Family functioning from an ecological systems perspective
· The impact of socioeconomic status
· Cultural values and public policies
The Influence of Alleles
In the argument over nature versus nurture in child development, nature is determined by genes passed down from parent to child during conception. Both parents pass genetic traits to their offspring, but different offspring may acquire different traits from each parent. Why do some children in one family have similar characteristics or appearances and yet other children in the same family look very different? The answer lies in the interaction of genes inherited from the mother and father.
Genes and alleles influence the inheritance of traits, through dominant–recessive inheritance, incomplete dominance, X-linked inheritance, genomic imprinting, mutation, and polygenic inheritance. In order to understand genetic inheritance, you need to understand the basics of how genes work, and how they work together with one another.
Understanding the basic structures and elements of genetics is essential to recognize how various traits are inherited, from appearance to intelligence.
The basic building block of the study of genetics is the gene; a gene is a single unit of genetic information.
A chromosome is a threadlike strand of DNA encoded with a large number of genes. Humans receive 23 chromosomes from each parent, for a total of 46 chromosomes.
An allele is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristics in the individual. Humans have two alleles, one from each parent, at each genetic locus, or position, on a chromosome.
The entire genetic makeup of an individual is called the genotype. The genotype can refer to the genetic makeup of an organism with reference to a single trait, set of traits, or an entire complex of traits. It can also refer to the sum total of genes transmitted from parent to offspring.
The phenotype is the appearance of an individual resulting from the interaction of the genotype and the environment, or the expression of the individual’s genes. You can see the phenotype when you look at someone–the phenotype includes expressed and observed traits. The genotype can include a range of traits that are not expressed or observable.The phenotype is determined by the a variety of factors, including how genes relate to one another in the individual, and how environmental factors impact the expression of various genes.
Patterns of Gene-Gene Interactions
Blue eyes are an example of a recessive trait
Genes interact with one another in a variety of different ways to produce genetic traits, ranging from eye color or height to a variety of genetic diseases. Genetic expression and inheritance is not simple. In this lesson, you will learn about some of the ways genes interact with one another and how their interactions define and change the expression of genetic traits.
The expression of many genes is defined by whether or not a gene is dominant or recessive. These terms describe how likely or unlikely it is for the offspring to express this gene, or for the genetic phenotype to appear in the offspring. Differences in the alleles can lead to different visible traits in the individual.
· The differences in the alleles can cause variations in the protein that’s produced by the gene, or they can change protein expression, including when, where, and how much protein is made. Proteins affect the expression of different traits, so variations in protein activity or expression can produce different phenotypes.
Incomplete Dominance Pattern
· Alleles are defined as dominant or recessive. If a dominant allele is present, that allele will be expressed. If a recessive allele is present, it will not be expressed if there is a dominant allele. Dominant and recessive genes were first identified by Gregor Mendel in the 19th century. While studying pea plants, Mendel recognized that the color of the flowers was determined by a dominant or a recessive gene.
The second allele in the pair of genes may be dominant as well, if two of the dominant genes are inherited, or it can be recessive. Think about eye color–while this is a simplified example, many people are familiar with it and it’s a relatively easy one to understand.
In eye color, brown eyes are dominant and blue eyes are recessive. If one parent has two dominant brown genes, represented by BB, all offspring will be brown eyed. If both parents have blue eyes or bb, offspring will be blue eyed. If one parent has brown eyes, but carries a recessive blue eye gene or has the genotype Bb, and the other parent is blue eyed or bb, the parents have a 50 percent chance of having a blue eyed child and a 50 percent chance of having a brown eyed child.
While eye color really doesn’t have a significant impact, other dominant and recessive traits can have a much greater impact on the individual’s life and well being. Some genetic illnesses are typically recessive traits. A healthy individual can carry the recessive gene without expressing signs of the illness. These individuals are called carriers. They do not express the gene, but carry it to the next generation and may pass it to their children. The child is only at risk if each parent carries a recessive gene that codes for the illness. Cystic fibrosis is a common example. If both parents have a recessive gene, the child may be born with cystic fibrosis, even though both parents appear healthy.
In some cases, the genetics associated with an illness of this sort provide other benefits. For instance, sickle cell anemia is a recessive disease that damages red blood cells. For individuals with two recessive sickle cell genes, the illness can be devastating. Individuals with only one copy to the recessive sickle cell gene, however, have a much lower risk of contracting malaria. Being a carrier offers benefits, but having two copies of the recessive gene causes illness.
In these examples, the dominant trait, if present, will be the one expressed. The recessive trait will only be expressed if the individual contains two recessive alleles. While some alleles are dominant and recessive, other alleles show different dominance patterns, including co-dominance and incomplete dominance.
Incomplete Dominance Pattern
· INTERACTIONS BETWEEN ALLELES
· INCOMPLETE DOMINANCE
· RECOGNIZING INCOMPLETE DOMINANCE
While some alleles are dominant and recessive, other alleles interact differently with one another. Where there are several different allele types for a single gene, they may interact differently with one another. They may not be dominant or recessive, but co-dominant.
Alleles that are co-dominant produce a different phenotype than dominant or recessive phenotypes. Blood type presents an effective way to consider co-dominance. You’re probably aware that there are several different blood types: A, B, O and AB. A and B are codominant types, while O is recessive. If you have a type O parent and a type A parent, you will be type A, as O is recessive. If you have a type A and a type B parent, you could end up type AB, if you inherit one type A allele and one type B allele. Co-dominant alleles are alleles that are both expressed in the phenotype-they are neither dominant or recessive.
Incomplete dominance allows aspects of both alleles to be expressed in the phenotype of the individual. For instance, a red flower that cross-breeds with a white flower might produce a white flower, a red flower, or a pink flower. The pink flower would be an example of incomplete dominance. If a black cat and a white cat produced black, white and gray kittens, this would also be an example of incomplete dominance, when the gray kittens show traits of both the black and the white parent.
When incomplete dominance occurs, aspects of both alleles will be expressed. Incomplete dominance may be recognized when the offspring shows a phenotype different from both parents; however, this is not an entirely accurate test for incomplete dominance. The different phenotype must show traits of both parental phenotypes.
X-linked pattern inheritance is another type of genetic inheritance and expression. X-linked traits are found on the X chromosome, one of two sex chromosomes. Females have two X chromosomes, while males have one X chromosome and one Y chromosome. X-linked traits are typically expressed only in males, rather than females.
· In females, the presence of one healthy functional gene and one unhealthy, missing or defective gene on the X chromosomes allow the healthy trait to be expressed or minimize the impact of the unhealthy gene. In a male, the defective x-linked genes are the only ones present, since the Y chromosome is different. In this case, the male may present with the X-linked inheritance.
A number of genetic disorders are x-linked, including hemophilia, a bleeding and clotting disorder, and Fragile-X, a disorder which causes developmental delays. Because of the X-linked inheritance, these disorders are prevalent and more severe in boys than in girls.
We inherit two copies of most genes and both genes are working, functional copies. Epigenetics defines how genes are expressed. In most cases, all epigenetic changes are stripped out of the genes soon after conception; the parental expression of genes does not therefore impact the offspring.
Some genes imprint or keep the epigenetic tags during the process of conception. Imprintation occurs in the genes found in the egg and sperm cells before conception occurs. The imprinted gene typically remains active, while the allele that is not imprinted will be inactive. When this process occurs normally, genetic development is typical.
When there is a problem in the inheritance of imprinted genes, significant genetic disorders may result. These can be the result of two active imprinted genes or two inactive imprinted genes. Health issues associated with gene imprintation include cancer and a number of severe health conditions. Diseases directly connected to gene imprinting include Prader-Willi Syndrome and Angelman Disease. Prader-Willi is associated with learning difficulties and uncontrollable eating, while Angelman Disease is linked to learning difficulties and an unusually happy disposition.
Epigenetic information is responsible for many of the challenges associated with cloning mammals. Some scientists believe that gene imprinting is the result of evolutionary competition among males for maternal resources; or the survival of their young over the young of other males.
· LIKELIHOOD OF MUTATIONS
Mutations are changes in the genetic sequence of an organism, and they are a main cause of diversity among organisms, particularly as expressed over time. Most mutations impact the nucleic acids, or acids that form DNA. These changes occur at many different levels, and they can have a range of different consequences. Some of these mutations may be positive or beneficial to the organism. Others may be negative, or damaging to the organism.
For organisms that reproduce, it is essential to classify mutations as heritable, or able to be passed down to the offspring and descendants or not heritable. Mutations that do not impact reproductive cells or hereditary material have little relevance overall, but can be responsible for individual differences. These are called somatic mutations, and do not impact the offspring or descendants of the individual or organism. An albino deer, for example, can be the same as other deer except for color.
· LIKELIHOOD OF MUTATIONS
Mutations are difficult to predict; however, certain types of mutations are more likely than others in some organisms. Mutation rates, overall, are very low–in many cases, mutation does not benefit the organism.
Polygenic inheritance is the interaction of different genes to produce a single phenotype. Skin color is an example of polygenic inheritance. Parents can pass on three different alleles controlling skin color and the amount of melanin present in the skin. In total, six different alleles work together to produce a single phenotype in the individual, or to determine how light or dark the individual’s skin is.
Some diseases are also the result of polygenic inheritance. These are genetic illnesses, apparent at birth. Cleft palate, a deformity in the palate of the mouth that creates an opening between the mouth and sinuses, and spina bifida, a deformity in the spinal development of the fetus, are the result of polygenic inheritance.
Unlike more direct forms of inheritance, environmental issues can directly impact polygenic inheritance. For instance, spina bifida is a neural tube defect. The risk of this defect is lowered if the mother has adequate supplies of folic acid in early pregnancy.
Ecological Systems and Family Functioning
The Ecological Systems Theory, also called the Human Ecology Theory, was formulated by psychologist Urie Bronfenbrenner. This theory addresses the difference between behavior at home, with family, and outside of the family. This theory strives to explain why individuals behave differently with family than they do at work or at school.
There are five environmental systems. Each of these involves different environments encountered during daily life. All environmental systems impact the child and the child’s ongoing development.
The kindergarten classroom is an example of a microsystem
FIVE ENVIRONMENTAL SYSTEMS
Bronfenbrenner and Ecological Systems Theory
Bronfenbrenner believed that the child was at the center of this progressive network of ecosystems, moving further than further out from the child. In order to understand the child’s development, psychologists must consider how the child functions and interacts with each of these individual ecosystems.
SYSTEMS OF A SIX-YEAR-OLD
For a child of six years, microsystems might include home, school, a sports team, and after-school child care. The mesosystem includes the interactions between those different microsystems. The exosystems in the child’s life might include the parents’ workplaces. The macrosystem is the child’s culture, determined by their socioeconomic status, ethnicity and other factors. The chronosystem could be a variety of life events, like the birth of a sibling.
ROLE OF THE FAMILY
The family, for Bronfenbrenner, plays the most critical role in the development of the child. In the family, children learn language, culture and values. They form lifelong bonds and attachments in the family, and when the family is healthy, are more capable of functioning in a healthy way in other relationships and environments.
Parents have a direct influence on children’s behavior, depending upon how they parent and structure the child’s environment. Indirect influences on children are interactions between two individuals that are impacted by an outside force or third party. Children can experience internal or external barriers to their relationships with different ecosystems. Internal barriers cause worry and fear, while external barriers are expressed as anger or aggression.
While Bronfenbrenner believed in the importance of these ecosystems in child development, genetics still played a role in the child’s overall experiences. Personality and other factors are influenced by genetics. In fact, two children can experience the same microsystem or family context in very different ways. Awareness of the contexts in which children develop and grow can help to understand those children, their behavior and their development.
The Ecological Systems Theory has been key to the work of many later psychologists, including their understanding of how various parts of life relate to one another.
Socioeconomic Status and Family Functioning
· SOCIOECONOMIC STATUS
· INCOME, EDUCATION, AND OCCUPATION
· MIXED INFLUENCES
· COMPARISON OF TWO FAMILIES
The socioeconomic status of the family significantly impacts the physical, psychological, social and intellectual development of children. According to the American Psychological Association, “Socioeconomic status (SES) is often measured as a combination of education, income and occupation. It is commonly conceptualized as the social standing or class of an individual or group. When viewed through a social class lens, privilege, power and control are emphasized.”
Imagine a pair of young parents, both still in college or graduate school. They have a very low income, but would not be of low socioeconomic status because of their education and occupation. They may have limited financial resources, but the children likely experience some of the benefits common to children from families with more resources. For instance, these parents likely understand the importance of early childhood literacy. Compare those parents to a young couple who dropped out of high school and work menial jobs; they may have the same approximate income as the first family, but their lives and socioeconomic status are very different.
Socioeconomic status is not just the result of income, but of a combination of income, education and occupation. Higher socioeconomic status is associated with higher levels of education, technical or white-collar jobs, and higher incomes. Lower socioeconomic status is closely associated with reduced education, unskilled or semi-skilled labor, and lower incomes. Each of the three factors that define socioeconomic status are relevant to determining the socioeconomic status of a family.
The differences can impact children in other ways as well. For instance, two families of a similar income, for instance comfortably middle class, can be very different depending upon the parents’ occupation, experiences and education. One family might believe it is essentially important for their children to develop a good work ethic, while the other might be more concerned with appearances. These differences are also the result of socioeconomic status.
Factors Linked to Low Economic Status
Several factors are specifically linked to low socioeconomic status. These include psychological, physical, educational, and familial issues.
· Psychological Impact
· Physical Impact
· School Performance
· Risk of Violence and Neglect
· Relationship Stress and Divorce
CONNECTIONS BETWEEN LOWER SOCIOECONOMIC STATUS AND CHILD DEVELOPMENT
Why does socioeconomic status have such an impact on children’s development and well-being? What mechanisms can help to alleviate that impact? Research since the 1930s has clearly shown a connection between family stress and economic hardship or low socioeconomic status. Current research findings have consistently shown connections between lower socioeconomic status and developmental issues for children.
EXTREME POVERTY AND HOMELESSNESS
EXTREME POVERTY AND HOMELESSNESS
Today, some 46 million Americans, or 15 percent of the population, live below poverty level. Extreme poverty, including homelessness, can impact a large number of children. Some 40 percent of the homeless population is made up of homeless youth and children; these children often suffer extreme stress, do poorly in school, and lack adequate access to health care and other resources.
Intervention Can Make a Positive Difference
In addition to recognizing correlation and causation between socioeconomic issues and child development, researchers also look at ways to address those disparities. While some steps, like working to increase education and improve a family’s socioeconomic status, address the cause, many interventions are designed to reduce the impact of low socioeconomic status, without changing the family’s socioeconomic status.
· Several key differences are noted between higher and lower socioeconomic status families.
o Higher status is associated with older parents, increased interest in learning and cognitive development, and increased support for curiosity.
o Lower status is associated with younger parents, increased emphasis on obedience, and reduced access to cognitive learning.
o Affluence, or wealth, may also be associated with poor child outcomes, including poor grades and increased risk of drug and alcohol abuse.
Early childhood interventions of different types have shown significant improvements in outcomes for children. This supports the causal link between low socioeconomic status and difficulties in children. Improvements in family income consistently improve conditions for children in those families; however, other types of interventions can also impact children’s well-being.
Two different theoretical concepts are applied to explain the changes observed in children as the result of increased socioeconomic status or early childhood intervention. The first of these is the Family Stress Model. The Family Stress Model suggests that children benefit from improved relationships and reduced family stress as a result of improved family income.
In the Family Stress Model, poor outcomes associated with low socioeconomic status are the result of increased parental stress. Stress causes the parents to parent less effectively, damaging their relationship with the children. Parents experiencing stress are likely to be harsh, uninvolved, and to lack the emotional resources necessary. As a result, the children struggle with a variety of psychological and educational issues. The Family Stress Model shows a direct path from indicators of economic hardship to economic pressure, then from economic pressure to parent emotional distress, from parent emotional distress to conflicts between parents, from conflicts between parents to disruptions in effective parenting behaviors, and finally from disruptions in parenting to child maladjustment.
The second of these is the Investment Model. The Investment Model suggests that increased economic resources allow families to increase their investment, both financially and in terms of time, in their children. Increased investment provides benefits to the children, physically, psychologically, intellectually and emotionally. These investments in children involve multiple dimensions of family support including parent interaction and support of learning, access to adequate food, housing and medical care, and improved surroundings, including living in a safe neighborhood with accessible resources. Children have access to more resources, including parental time, as the family’s socioeconomic status improves.
Interventions in early childhood often rely upon the Investment Model. In this case, resources are provided to parents or children to increase the investment in the child’s learning experiences. For instance, children might be provided with free pre-school, increased access to books and learning materials, or parents might have access to parenting classes and educational resources.
Early access to learning materials, including books, is closely correlated with educational success. Improvements in neighborhoods and schools can also help to alleviate issues associated with low socioeconomic status. Schools can work to involve parents, and communities can work together to create safe and supportive spaces.
Today, both the Family Stress Model and the Investment Model are considered valid. The Family Stress Model may have an increased impact on children’s emotional development and well-being. The Investment Model appears to be more relevant with regard to children’s cognitive development. Regardless of socioeconomic status, families that are involved, affectionate and warm produce healthier and happier children. This can take many forms, but the family dinner is a popular indicator for family closeness. Socioeconomic status can also have an impact on family culture, and how public policies impact that culture.
Influence of Family Values and Policies
While socioeconomic status and ecological systems of family functioning impact children, children are also impacted in a variety of ways by the values and culture of the family, as well as public policies regarding children. Each of these impact and change how children develop and how they experience the world around them.
Culture can determine how much parents value curiosity and experimentation.
PARENTS PASS ON CULTURE, VALUES, BELIEFS
When parents interact with children, they do more than develop relationships. They also pass down information about culture, values and beliefs. In addition, other adults also pass down similar information, including teachers, care providers, doctors, friends and family. Policymakers also have their own values, beliefs and cultural preferences. This can cause conflicts between parents and caregivers, as well as confusion for children. In addition, policymakers may have different beliefs and values than families, particularly families of lower socioeconomic status.
A number of different factors can impact cultural values. What is culture? The definition adopted by the early childhood organization, Zero to Three is, “Culture is a shared system of meaning, which includes values, beliefs, and assumptions expressed in daily interactions of individuals within a group through a definite pattern of language, behavior, customs, attitudes, and practices”. This definition specifies several key factors. First, culture is shared among individuals; it is not the beliefs of a single person.
CULTURE’S CONTRIBUTIONS TO CHILD DEVELOPMENT
Culture provides tools for individuals to create scripts that they use to engage with and understand their environment and others in their environment. These cultural scripts become fully ingrained; they are not conscious, but rather considered, by the individual, to be simply the way things are. Culture is changeable, and may develop and adapt over time. While culture develops from interactions with the environment, including interactions with parents and caregivers, culture is not the same as ethnicity
IMPACT OF CAREGIVER’S CULTURE
First and foremost, individuals, particularly teachers, caregivers, and therapeutic professionals should recognize their own cultural perspective. For many professionals, their “culture of origin” or culture they grew up in and perspective that they developed is largely European American. There may be clashes and confusion between the values of the caregiver’s culture of origin and the parents’ and child’s culture of origin.
· CULTURAL DIFFERENCES
· CULTURAL SENSITIVITY
Parents and caregivers may, as the result of differing cultures of origins, have different beliefs about many aspects of child rearing.
· They may have a different vision of what success looks like for the child.
· They may have differing views on well-being for the child.
· They can have varied views on behavior and discipline, and therefore, different expectations of children’s behaviors and interactions.
· Caregivers, teachers, and others who associate with children and families can increase their cultural sensitivity in a number of different ways. First and foremost, caregivers can familiarize themselves with other cultural scripts than their own. One way to do this is to speak to parents about the type of adult they envision their child becoming. The individual they describe will help caregivers to recognize parents values.
· Individualist versus Independent Culture
· Some broad terms can be used to define cultures. Cultures are defined as individualist or interdependent.
Culture’s Impact on Development
Culture can also impact language development in young children. Multiple studies have shown that young children develop language through exposure. Language exposure has been linked to both culture and socioeconomic status. The sequence of language development is the same in all languages; however, the further development of language can depend upon access to various resources, including conversation, books and other learning materials. Access to language impacts children’s vocabulary growth, vocabulary use, and IQ scores at age three.
The cultural values of the dominant culture impact the development and priorities of public policy, including government funding for various issues that impact children and often, research into child development. Many different types of public policy impact children’s health, well-being and development, including funding for anti-poverty programs, access to early childhood education, and even health care policy. Voters are predominantly older, white and economically successful, leading to reduced access to these aid and support for childhood programs.
Programs that provide access to job training and higher education, improve access to food and safe housing, and that enable regular access to healthcare can all have a beneficial impact on child development. As noted, children in more financially stable homes show improved intellectual and emotional development. Programs that increase financial stability for families with children can benefit the overall development of those children. Cuts to these programs can damage families and the development of children. For instance, cuts to welfare programs and work requirements may limit access to food and resources and increase familial stresses.
Other examples of programs like these include the school breakfast and lunch programs. Providing free or reduced cost meals to children at school provides them with access to adequate and healthy food and is another example of social welfare programs designed to address the needs of children
Government policy also impacts the availability of early childhood education. Childhood advocates typically recommend broad access to early childhood education for children of all social classes. For children of a higher socioeconomic status, these programs have relatively little impact. These children have access to early childhood education resources, regardless of public policy. For children of lower socioeconomic status, public funding for early childhood education can have a dramatic impact on their later educational success. Federal funding for early childhood education pays for child care assistance, Early Head Start and Head Start preschool programs for children of lower income families, and improvements in elementary and secondary education.
· PUBLIC POLICIES ADDRESS SOCIAL PROBLEMS
· FINANCIAL HELP
· CIVIL RIGHTS OF CHILDREN
When public policy values child development and the well-being of children, some of the differences associated with both genetics and environmental factors can be alleviated. Good quality childcare and early childhood education can provide children from different cultural and socioeconomic backgrounds with improved access to a wide variety of learning resources.
Anti-poverty programs of various sorts can reduce financial stresses for families, and help to improve the family and child’s socioeconomic status. Various organizations continue to work for the well-being of children, including the Children’s Defense Fund. This non-profit organization works for the good of children by funding research, community activity, and legislative activity
The International Convention on the Rights of the Child is an international agreement supporting basic rights of all children. These include the right to freedom of thought and religion, access to free and appropriate education, a loving family life, and access to good health and an adequate standard of living. The United States is one of only two developed countries which have not ratified the Convention on the Rights of the Child, in part because of the belief in individualism and rejection of legal controls on parenting.
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