Transcript HDChap2Student - University of West Florida

Lecture 2
Genetics and Prenatal Development
DEP 2004 & 2004H Human Development Across the Lifespan
Erica Jordan, Ph.D., University of West Florida
School of Psychological and Behavioral Sciences
S
Lecture Guiding Questions
S How do genes influence behaviors?
S What are the major stages of prenatal development?
S What risks factors are associated with prenatal
development?
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
How do genes influence
behaviors?
S Behavior Genetics: the branch of genetics that deals with
inheritance of behavioral and psychological traits
S Traits controlled by a single gene typically produce one of two
outcomes (either - or)
S Most behavioral and psychological traits are more complex
S
S
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Possible phenotypes fall along a continuum or have multiple
possibilities
Result from the instructions/interactions of separate genes—polygenic
inheritance
Influence of each specific gene involved is very difficult to determine
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Research Methods Commonly Used
to Study Behavioral Genetics
S Twin studies
S Comparison of monozygotic twins (identical and from the same
fertilized egg) and dizygotic twins (fraternal and from different
eggs).
S Characteristics commonly shared by monozygotic twins that are
often different in dizygotic twins are typically inherited.
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
S Adoption studies
S Comparing adopted children alongside their biological parents
and their adoptive parents.
S Studying DNA
S Taking samples of DNA from individuals who differ in some
way then examining the DNA for differences.
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
More about the way genes
influence behaviors:
1.
The behavioral consequences of genetic instructions depend on
the environment in which those instructions are implemented.
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A specific genotype does not always lead to the same
phenotype.
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Reaction range—range of potential phenotypes for a
specific genotype.
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Heritability estimate—extent to which genes are responsible
for the differences among people; range from 0 to 1.00.
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
2.
Heredity and environment interact dynamically throughout
development.
3.
Genes can influence the kind of environment to which a
person is exposed.
- Responses from others
- Niche picking—refers to how people seek out their own
environments based on their interests and strengths
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
4.
Environmental influences typically make children within a
family different.
- Siblings often have similar experiences
- Nonshared environmental influences also occur
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
The Theory of Genotype 
Environment Effects
S Passive genotype  environment effects
S Evocative genotype  environment effects
S Active genotype  environment effects
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
From Conception to Birth
S Prenatal Development
S The changes that turn a fertilized egg into a newborn human
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Period of the Zygote
(Week 1 - 2)
S Zygote: fertilized egg
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Period of the Embryo
(Week 3 - 8)
S Begins when zygote is completely embedded in the
uterine wall.
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Period of the Fetus
(Weeks 9 - 38)
S Final and longest phase of prenatal development. Begins
when cartilage begins to turn to bone and ends at birth.
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Common Genetic Disorders
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Sickle-cell desease
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PKU
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Huntington’s disease
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Down syndrome
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Klinefelter’s syndrome
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Turner’s syndrome
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XYY complement
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XXX syndrome
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Risks to Prenatal Development
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Parents’ age
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Nutrition
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Stress
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Disease
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Drugs
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Environmental hazards
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Teratogens—agents that cause abnormal prenatal development
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View
Teratogens: Five Principles
Adapted from Arnett's (2012) Human
Development: A Cultural Approach &
Kail & Cavanaugh's Human
Development: A Life-Span View