growth and lifespan Flashcards
genotype
genetic makeup; language of dominant and recessive traits that inform an organism’s phenotype.
phenotype
observed characteristics; combination of genotype and environment.
Bronfrenbrenner’s ecological models
a model that addresses the interconnected environments that all impact a child’s development. consists of the micro, meso, exo, macro, and chrono systems.
microsystem
the system most immediate to the child.
e.g. their family or classroom
mesosystem
the interactions between the child’s different environments.
e.g. the relationship between a child’s home and their school.
exosystem
environments that indirectly impact the child’s life.
e.g. a parent’s workplace.
macrosystem
the broader cultural context a child lives in.
e.g. cultural practices or governmental shifts
chronosystem
monumental events that occur within a child’s lifespan that can positively or negatively impact how they develop.
e.g. the birth of a sibling or the death of a parent.
Rutter’s indicators of adversity
six family risk factors; the more risk factors, the greater likelihood of negative outcomes.
1. severe marital discord
2. low SES
3. overcrowding/large family
4. paternal criminality
5. maternal psychopathology
6. out-of-home care
Werner and Smith
longitudinal study on resiliency factors in children born with prenatal stress. found that the 3 biggest factors of resiliency were:
1. a stable relationship with a caregiver
2. fewer stressor following birth
3. easy temperament
critical period
a predetermined, unyielding period of time in which some sort of milestone is expected in biological maturation.
sensitive period
longer in duration and more flexible than a critical period in which a developmental milestone is expected to be achieved.
What does the nature-nurture controversy refer to?
Disagreements about the relative roles of genetic and environmental influences on development
Most developmental psychologists agree that both factors play a role, but their emphasis varies.
What are the three main mechanisms of inheritance?
- Single gene-pair inheritance
- Sex-linked inheritance
- Polygenic inheritance
Each mechanism explains how characteristics are influenced by genetic factors.
What is single gene-pair inheritance?
Occurs when a characteristic is influenced by a single pair of genes
This can involve two recessive genes or one recessive and one dominant gene.
What is sex-linked inheritance?
Occurs when a characteristic is influenced by a gene on one of the sex chromosomes, most often the X chromosome
This type of inheritance can result in sex-specific traits.
What is polygenic inheritance?
Occurs when a characteristic is influenced by multiple genes
Most characteristics, such as height and intelligence, are polygenic.
Define heritability estimates.
Indicate the extent to which variability in phenotype in a given population is attributable to differences in genotype
Phenotype refers to observed characteristics; genotype refers to genetic inheritance.
What does a heritability estimate of .80 for height indicate?
80% of variability in height in the population is due to genetic factors
The remaining 20% is attributed to environmental factors.
How does socioeconomic status (SES) affect intelligence heritability estimates?
- About .10 for young children from low-SES families
- About .70 for young children from high-SES families
This indicates that environmental factors can significantly influence heritability.
What have adoption studies shown regarding intelligence and SES?
Adopted children from low-SES families raised in high-SES families have higher IQ scores than their siblings who remained in low-SES environments
This suggests that enriched environments and educational opportunities impact intelligence.
What were the average IQ scores found in Capron and Duyme’s (1989) study?
- High-SES born and adopted: 120
- Low-SES born and adopted by high-SES: 107
- High-SES born and adopted by low-SES: 104
- Low-SES born and adopted: 92
This study illustrates the impact of SES on IQ across different family environments.
What is a critical period in the context of environmental impact on development?
A limited period of time when exposure to certain environmental events is necessary for development to occur.
Critical periods are essential for certain developmental milestones and if missed, may lead to permanent deficits.
How does a sensitive period differ from a critical period?
A sensitive period is usually longer than a critical period and is optimal (but not necessary) for certain environmental events to occur.
Sensitive periods allow for development to occur but are not strictly limited in time.
What is Bronfenbrenner’s ecological theory?
A theory that describes development as involving interactions between a person and their environment, distinguishing between five environmental systems.
This theory emphasizes the importance of multiple environmental layers affecting development.
What does the microsystem include?
The child’s immediate environment, including relationships with parents, siblings, friends, and others at home, school, and church.
The microsystem represents the most direct influences on a child’s development.
What is the mesosystem?
It refers to interactions between elements of the child’s microsystem, such as family relationships affecting school interactions.
The mesosystem highlights the connections between different microsystems.
What elements are included in the exosystem?
Elements that affect the child’s immediate environment, including parents’ workplaces, extended family, and community health services.
The exosystem includes influences that are not directly experienced by the child but still impact their development.
Define the macrosystem.
The social and cultural environment, including cultural practices, economic conditions, and political ideologies.
The macrosystem encompasses broader societal factors that influence development.
What is the chronosystem?
Environmental events that occur over a person’s lifespan and impact development and circumstances, such as parental divorce or natural disasters.
The chronosystem considers the timing and duration of life events and their effects.
What is fetal programming?
The theory that environmental events in utero during sensitive windows of development can have permanent and long-lasting effects.
Fetal programming emphasizes the importance of prenatal conditions on long-term health.
Who is associated with the fetal origins hypothesis?
Barker and colleagues, who found links between prenatal undernutrition and increased risk for coronary heart disease and type 2 diabetes in adulthood.
Barker’s research laid the foundation for understanding how prenatal conditions affect lifelong health.
What adaptations occur due to undernutrition during prenatal development?
Adaptations that sustain a fetus’s development in utero but permanently change the structure and function of organ systems.
These adaptations may predispose the offspring to future health problems.
True or False: Prenatal exposure to environmental factors has been linked to increased risk for certain health disorders.
True.
Research indicates that various prenatal exposures can lead to both physical and mental health issues later in life.
What is one mechanism that explains the link between maternal stress in utero and future health risks?
Prenatal programming of the hypothalamic-pituitary-adrenal (HPA) axis.
The HPA axis is involved in stress response and can influence cardiovascular, metabolic, and mental health outcomes.
What is the average heritability estimate for intelligence?
0.50
This estimate varies with age.
How does the heritability estimate for intelligence change with age?
- About 0.20 for infants
- About 0.40 for children and adolescents
- 0.60 to 0.80 for early and middle adulthood
- 0.60 for adults over 80 years of age
These estimates indicate an increasing genetic influence with age.
What type of studies confirm the influence of genetics on intelligence?
- Twin studies
- Family studies
- Adoption studies
These studies show that genetic factors significantly affect intelligence.
What do adoption studies reveal about the correlation of IQ scores?
Children’s IQ scores correlate more with biological parents than adoptive parents.
This correlation increases as adopted children age.
What is the concept of active genotype-environment correlation?
Niche-picking, where individuals seek experiences that fit their genetic predispositions.
This explains the increasing influence of genetics on intelligence over the lifespan.
How do shared environmental factors influence intelligence across the lifespan?
- Large influence in early childhood
- Decreases during adolescence and early adulthood
- Stabilizes at a low level in middle and late adulthood
Non-shared factors maintain a relatively low influence throughout the lifespan.
What is the correlation coefficient for identical twins reared together?
0.85
This indicates a strong genetic influence on IQ.
What correlation coefficient is observed for fraternal twins reared together?
0.58
This is lower than that of identical twins, indicating less genetic similarity.
Define behavioral genetics.
The study of how genetic variation affects psychological traits, including cognitive abilities and personality.
Behavioral genetics often uses data from twin, adoption, and twin-adoption studies.
What is the purpose of twin studies in behavioral genetics?
To compare correlation coefficients of traits between monozygotic and dizygotic twins.
A significant difference supports the influence of genetics.
What assumption underlies twin studies?
The equal environment assumption, which posits that monozygotic and dizygotic twins have similar environments.
This assumption has been challenged by evidence of differing treatment by parents.
Why are adoption studies considered more powerful than twin studies?
They do not rely on the equal environment assumption.
This allows for clearer distinctions between genetic and environmental influences.
What do twin-adoption studies combine?
The strengths of twin studies and adoption studies.
They compare traits of monozygotic twins reared together and apart.
What does a similar correlation coefficient for twins reared together and apart suggest?
Genetics has a greater impact on the trait than environmental factors.
A substantial difference indicates strong environmental influences.
What is genotype-environment correlation?
A person’s genetic make-up affects their characteristics directly and indirectly by influencing their environments
Proposed by Scarr and colleagues, it includes passive, evocative, and active correlations.
What are the three types of genotype-environment correlations?
- Passive genotype-environment correlation
- Evocative genotype-environment correlation
- Active genotype-environment correlation
These correlations describe how genetic predispositions interact with environmental factors.
What is passive genotype-environment correlation?
Occurs when children inherit genes that predispose them to certain characteristics and are exposed to supportive environments provided by their parents
Example: Sociable children of sociable parents who provide social opportunities.
Define evocative genotype-environment correlation.
A child’s genetic make-up evokes reactions from others that reinforce their genetic traits
Example: A sociable child encourages social responses from others.
What is active genotype-environment correlation?
Also known as niche-picking, it occurs when children actively seek experiences that fit their genetic predispositions
Example: Sociable children seeking social interactions.
How does the importance of genotype-environment correlations change over time?
Passive and evocative types are most important in infancy and early childhood, while active type becomes more important as children gain independence.
What is reaction range?
The range of possible outcomes for certain traits influenced by genetic make-up and environmental factors
Example: A child with a mild intellectual disability may have better outcomes in a rich environment than one with a severe disability.
What does canalization refer to?
The tendency for genetic make-up to restrict developmental outcomes regardless of environmental circumstances.
What is Dynamic Systems Theory (DST)?
A theory that emphasizes the interaction of biology, environment, self-control, social interactions, and cognitive representation in development
Advocates include Thelen and colleagues, who studied motor skill development.
What are rhythmic stereotypies in the context of DST?
Simple repetitive behaviors that precede the emergence of voluntary complex behaviors
Examples include kicking and reaching that lead to crawling.
How do individual characteristics affect motor milestone development?
Motor milestones emerge in sequence but develop variably based on infant characteristics, environmental factors, and the infant’s goals.
What is epigenetics?
The study of changes in organisms caused by modifications in gene expression rather than changes in the genetic code
Epigenetic mechanisms can alter phenotype without changing genotype.
What is DNA methylation?
The addition of a methyl group to DNA that prevents certain genes from being expressed
It is one of the best-understood epigenetic mechanisms.
What environmental factors can cause epigenetic changes?
- Diet
- Environmental pollutants
- Child abuse
These factors can modify gene expression and lead to phenotypic changes.
Can epigenetic changes be passed down to future generations?
Yes, certain epigenetic changes can be inherited by descendants.
What are the three periods of prenatal development?
- Germinal period
- Embryonic period
- Fetal period
What is the germinal period?
Extends from conception to the end of the second week when the zygote implants on the uterine wall
What happens if there is exposure to teratogens during the germinal period?
Has an ‘all-or-none’ effect; significant damage prevents implantation, while little or no effect allows implantation
What is the embryonic period?
Extends from the third through the eighth weeks, during which major organs and structures are forming
Why is the embryonic period critical regarding teratogen exposure?
Exposure is most likely to cause major defects
What is the fetal period?
Begins when major organs have formed and extends from weeks 9 through birth
What are the effects of teratogens during the fetal period?
Most likely to cause minor defects or abnormalities
What is the age of viability?
The earliest age at which a premature baby can survive outside the womb, occurring between 22 and 26 weeks
What are the three trimesters of pregnancy?
- First trimester (weeks 1-13)
- Second trimester (weeks 14-27)
- Third trimester (week 28-birth)
What are chromosomal abnormalities?
Include chromosomal deletions, extra chromosomes, and missing chromosomes
What is Prader-Willi syndrome caused by?
A deletion on the paternal chromosome 15
What are common symptoms of Prader-Willi syndrome?
Narrow forehead, almond-shaped eyes, short stature, hypotonia, global developmental delays, hyperphagia, obesity, hypogonadism, intellectual disabilities
What is Angelman syndrome usually caused by?
A deletion on the maternal chromosome 15
List symptoms of Angelman syndrome.
- Microcephaly
- Wide jaw and pointed chin
- Severe developmental delays
- Communication and intellectual disabilities
- Hyperactivity
- Ataxia
- Seizures
- Hand-flapping
What is Cri-du-chat syndrome caused by?
A deletion on chromosome 5
What are symptoms of Cri-du-chat syndrome?
- High-pitched cry
- Intellectual disability
- Developmental delays
- Microcephaly
- Low birth weight
- Weak muscle tone
- Characteristic facial features
What causes Klinefelter syndrome?
Presence of two or more X chromosomes in addition to a single Y chromosome
What are symptoms of Klinefelter syndrome?
- Incomplete development of secondary sex characteristics
- Gynecomastia
- Low testosterone
- Long arms and legs
- Taller than normal
- Learning disabilities
What causes Turner syndrome?
Partial or complete deletion of one of the X chromosomes
List symptoms of Turner syndrome.
- No development of secondary sex characteristics
- Infertility
- Short stature
- Stubby fingers
- Drooping eyelids
- Web-like neck
What is Rett syndrome?
An X-linked dominant disorder usually caused by mutations in the MECP2 gene, almost exclusively affecting females
What are the characteristic symptoms of Rett syndrome?
- Slowed head and brain growth
- Loss of speech and motor skills
- Abnormal hand movements
- Sleep disturbances
- Breathing abnormalities
- Seizures
What is Down syndrome classified as?
An autosomal disorder due to an abnormality on a chromosome that is not a sex chromosome
What are the three types of Down syndrome?
- Trisomy 21
- Mosaic trisomy 21
- Translocation trisomy 21
What is the most common type of Down syndrome?
Trisomy 21
What causes trisomy 21?
Presence of an extra 21 chromosome in all cells of the body
What are common symptoms of Down syndrome?
- Intellectual disability
- Hypotonia
- Short stocky build
- Wide face
- Thick tongue
- Almond-shaped eyes
- Developmental delays
What factors increase the risk of having a baby with trisomy 21?
Older maternal age, especially after 30 years
What is the cause of translocation trisomy 21?
Can be due to an error during cell division or inherited from a parent carrier
What are genetic disorders caused by?
One or more abnormal genes.
What type of genetic disorder is Huntington’s disease?
Autosomal dominant disorder.
What is the inheritance probability of Huntington’s disease if one parent has it?
50% chance.
What is the inheritance probability of Huntington’s disease if both parents have it?
75% chance.
What type of genetic disorder is Phenylketonuria (PKU)?
Autosomal recessive disorder.