Early Influences on Development – Nature vs. Nurture

Question 1

What does the nature-nurture controversy refer to?

Answer 1

The nature-nurture controversy refers to disagreements about the relative roles of genetic and environmental influences on development. Most developmental psychologists agree that both play a role, but their theories differ in terms of emphasis. Some psychologists emphasize the stability of certain characteristics and stress the role of heredity; others emphasize the plasticity of some characteristics and stress the role of early experience (Berk, 2010).

Question 2

In terms of impact of Heredity on Development, what are the three main mechanisms of inheritance?

Answer 2

Single gene-pair inheritance
Sex-linked inheritance
Polygenic inheritance

Question 3

When does single gene-pair inheritance occur?

Answer 3

When a characteristic is influenced by a single pair of genes (two recessive genes or one recessive and one dominant gene).

Question 4

What do the barbiturates include?

Answer 4

Thiopental (Pentothal), amobarbital (Amytal), and secobarbital (Seconal).

Question 5

When does sex-linked inheritance occur?

Answer 5

Sex-linked inheritance occurs when a characteristic is influenced by a gene on one of the sex chromosomes, most often the X chromosome.

Question 6

When does polygenic inheritance occur?

Answer 6

Polygenic inheritance occurs when a characteristic is influenced by multiple genes. Most characteristics – e.g., height, weight, hair color, intelligence, and susceptibility to cancer – are polygenic.

Question 7

When does heritability estimate indicate?

Answer 7

Heritability estimates indicate the extent to which variability in phenotype in a given population is attributable to differences in genotype:

Question 8

What does Phenotype refer to?

Answer 8

Phenotype refers to observed characteristics, which are due to a combination of genetic and environmental factors.

Question 9

What does genotype refer to?

Answer 9

Genotype refers to genetic inheritance. For instance, the heritability estimate for height is .80, which means that 80% of variability in height in the population is due to genetic factors, while the remaining 20% is due to environmental factors.

Question 10

What does the heritability estimates indicate?

Answer 10

The research has confirmed that heritability estimates vary, not only for different characteristics, but also for the same characteristic in different age groups and different contexts.
As an example, heritability estimates for IQ are about .50 for children and .80 for adults and about .10 for young children from low-SES families and .70 for those from high-SES families (Berk, 2010; Turkheimer, Haley, Waldron, D’Onofrio, and Gottesman, 2003).

Question 11

In terms of the role of the environment, what are researchers interested in?

Answer 11

Some researchers interested in the impact of the environment on development distinguish between critical and sensitive periods.

Question 12

In terms of the role of the environment what is a critical period?

Answer 12

A critical period is a limited period of time when exposure to certain environmental events is necessary for development to occur.

Question 13

In terms of the role of the environment what is a sensitive period?

Answer 13

In contrast, a sensitive period is usually longer than a critical period and is a period of time when it’s optimal (but not necessary) for certain environmental events to occur. According to these researchers, sensitive periods are more applicable than critical periods to most aspects of human development.

Question 14

How do contemporary researchers distinguish between critical and sensitive periods?

Answer 14

However, many contemporary researchers do not distinguish between critical and sensitive periods but, instead, use the terms interchangeably.

Question 15

The impact of the environment is addressed by Bronfenbrenner’s (2004) ecological theory?

Answer 15

The impact of the environment is addressed by Bronfenbrenner’s (2004) ecological theory, which describes development as involving interactions between a person and his or her environment and distinguishes between five environmental systems.

Question 16

What are the five environmental systems for Bronfenbrenner’s?

Answer 16

Microsystem
Mesosystem
Exosystem
Macrosystem
Chronosystem

Question 17

What is the Bronfenbrenner’s microsystem?

Answer 17

The microsystem is the child’s immediate environment and includes the child’s relationships with parents, siblings, friends, and others at home, school, and church.

Question 18

What is the Bronfenbrenner’s Mesosystem?

Answer 18

The mesosystem refers to interactions between elements of the child’s microsystem – for example, the influence of family relationships on the child’s relations with peers and teachers at school, and vice versa.

Question 19

What is the Bronfenbrenner’s Exosystem?

Answer 19

The exosystem consists of elements in the environment that affect the child’s immediate environment and include the parents’ places of work, the extended family, and community health services.

Question 20

What is Bronfenbrenner’s Macrosystem?

Answer 20

The macrosystem is comprised of the social and cultural environment. It consists of cultural practices, economic conditions, and political ideologies.

Question 21

What does Bronfenbrenner’s the chronosystem consist of?

Answer 21

The chronosystem consists of environmental events that occur over a person’s lifespan and impact the person’s development and circumstances. It includes such things as parental divorce and job loss, the birth of a sibling, and natural disasters.

Question 22

What is fetal programming theory?

Answer 22

Fetal programming “is the theory that environmental events in utero during sensitive windows of development can have permanent and long-lasting effects” (Pelch, Allison, & Nagel, 2011, p. 45-1).

Question 23

What is fetal programming theory also known as?

Answer 23

It (fetal programming theory) is also known as Barker’s fetal origins hypothesis because it is derived primarily from the work of Barker and colleagues (e.g., Barker, Winter, Osmond, Margetts, & Simmonds, 1989) who found that undernutrition during prenatal development is predictive of an increased risk for coronary heart disease and type 2 diabetes in adulthood.
According to Barker, undernutrition causes adaptations that sustain a fetus’s development in utero but permanently change (program) the structure and function of organ systems in ways that predispose the offspring to future health problems.

Question 24

What has subsequent research shown as it relates to Barker’s theory?

Answer 24

Subsequent research has shown that prenatal exposure to other environmental factors is linked to increased risk for certain physical and mental health disorders and has identified mechanisms that are responsible for these links. For example, there is evidence that prenatal programming of the hypothalamic-pituitary-adrenal (HPA) axis may be the mechanism that explains the link between exposure to maternal stress in utero and the offspring’s increased risk for future cardiovascular, metabolic, and mental disorders (Howland, Sandman, & Glynn, 2017).

Question 25

Intelligence is influenced by both ______ and the _________.

Answer 25

Research has confirmed that intelligence (as measured by IQ) is influenced by both heredity and the environment.

Question 26

Ask Hailey how we should organize this

Answer 26

The following table lists the median correlation coefficients for people with different degrees of genetic similarity (Bouchard & McGue, 1981):
Median Correlations for IQ Scores

Relationship

Correlation

Identical twins reared together

.85

Identical twins reared apart

.67

Fraternal twins reared together

.58

Biological siblings reared together

.45

Biological siblings reared apart

.24

Half-siblings reared together

.35

Adopted siblings reared together

.31

Biological parent and child (together)

.39

Biological parent and child (apart)

.22

Adoptive parent and adopted child

.18

Question 27

Explanations for the impact of genetic and environmental factors on development include the following?

Answer 27

1. Genotype-Environment Correlation
2. Reaction Range
3. Dynamic Systems Theory (DST
4. Epigenetics

Question 28

What does the Genotype-Environment Correlation propose?

Answer 28

Scarr and her colleagues (Scarr, 1992; Scarr & McCartney, 1983) have proposed that a person’s genetic make-up not only affects a person’s characteristics directly but also indirectly by influencing the environments the person is exposed to.

Question 29

Describe Scarr’s Genotype-Environment 3 genotype correlations?

Answer 29

(a) Passive genotype-environment correlation
(b) Evocative genotype-environment correlation
(c) Active genotype-environment correlation

Question 30

When does Scarr’s Passive genotype-environment correlation occur?

Answer 30

When children inherit genes from their parents that predispose them to have certain characteristics and are exposed to environments by their parents that support the development of those characteristics. For example, the children of sociable parents are likely to be genetically predisposed to being sociable, and their parents will provide them with many opportunities to participate in social activities.

Question 31

When does evocative genotype-environment correlation occur?

Answer 31

Evocative genotype-environment correlation occurs when a child’s genetic make-up evokes certain kinds of reactions from parents and other people that reinforce the child’s genetic make-up. A sociable child will react to others in ways that encourage them to respond to the child in socially reinforcing ways.

Question 32

When does active genotype-environment correlation occur?

Answer 32

Active genotype-environment correlation is also referred to as niche-picking and occurs when children actively seek experiences that “fit” their genetic predispositions. Sociable children and adolescents will actively seek opportunities for social interactions.

Question 33

What does Scarr propose about the importance of the three genotype environment correlations?

Answer 33

Scarr also proposes that the importance of the three genotype-environment correlations changes over time: The passive and evocative types are most important in infancy and early childhood when children have little control over their environments, while the active type becomes increasingly important over time as children become more independent and able to choose their own niches.

Question 34

Explanations for the impact of genetic and environmental factors on development include the following?

Answer 34

1. Genotype-Environment Correlation
2. Reaction Range
3. Dynamic Systems Theory (DST
4. Epigenetics

Question 35

What does Gottesman’s reaction range theory?

Answer 35

According to Gottesman (1963), there’s a reaction range for certain traits that determines how people respond to environmental influences. In other words, genetic make-up determines whether the reaction range for a particular characteristic is broad or narrow. For example, a child born with a genetic defect that produces mild intellectual disability will have a broader range of positive outcomes from being provided with an enriched environment than a child whose genetic defect produces severe intellectual disability.

Question 36

What does canalization refer to in relation to Gottesman’s reaction range theory?

Answer 36

The tendency for genetic make-up to restrict developmental outcomes regardless of environmental circumstances is referred to as canalization.

Question 37

Explanations for the impact of genetic and environmental factors on development include the following?

Answer 37

1. Genotype-Environment Correlation
2. Reaction Range
3. Dynamic Systems Theory (DST)
4. Epigenetics

Question 38

What does Dynamic Systems Theory describe?

Answer 38

DST regards both nature and nurture to be essential for development. It’s based on the assumption that development is not simply the result of physical maturation but, instead, “is a complex process that involves the interaction of biology, environment, how we control ourselves and interact with others, and how we think about, or represent, our experiences in our minds” (Levine & Munsch, 2014, p. 57).

Question 39

Who were the first advocates of DST?

Answer 39

Among the first advocates of DST were Thelen and her colleagues (Thelen, 1995; Thelen & Smith, 1994) who used it to explain the development of crawling, walking, reaching, and other motor skills.

Question 40

What did the 2 results of Thelen’s Dyanamic System Theory indicate?

Answer 40

They concluded that simple repetitive behaviors (“rhythmic stereotypies”) precede the emergence of voluntary complex behaviors: For example, kicking, reaching, and rhythmic rocking while on all fours precede and are integrated to become crawling when crawling is supported by the situation. In other words, crawling and other motor milestones don’t suddenly emerge as the result of brain and body maturation.

They also concluded that, while major motor milestones emerge in the same sequence and at about the same age for all infants, the specific ways these milestone develop vary, depending on characteristics of the infant (e.g., perceptual ability, activity level), characteristics of the infant’s physical and social environment (e.g., physical barriers, social support), and the infant’s goals and desires (e.g., to obtain a toy on the other side of the room).

Question 41

Explanations for the impact of genetic and environmental factors on development include the following?

Answer 41

1. Genotype-Environment Correlation
2. Reaction Range
3. Dynamic Systems Theory (DST)
4. Epigenetics

Question 42

What are Epigenetics as they related to the impact of genetic and environmental factors on development?

Answer 42

Epigenetics is “the study of changes in organisms brought about by modification of gene expression, rather than by alteration of the genetic code in the form of DNA” (Launer, 2016, p. 183). In other words, epigenetic mechanisms cause changes in phenotype without changing genotype by altering the function or expression of genes.

Question 43

What are some of the epigenic mechanisms that have been identified?

Answer 43

1) The best understood is DNA methylation, which involves “the addition of a methyl group, or a ‘chemical cap,’ to part of the DNA molecule, which prevents certain genes from being expressed” (Rettner, 2013, para.
2) Environmental and psychosocial factors that have been identified as potential causes of epigenetic changes include diet, environmental pollutants, and child abuse.
3) Finally, there’s some evidence that certain epigenetic changes in an individual can be passed down to one or more generations of descendants of that individual (Masterpasqua, 2009).