 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

Lecture Guiding Questions  How do genes influence behaviors?  What are the major stages of prenatal development?  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?  Behavior Genetics: the branch of genetics that deals with inheritance of behavioral and psychological traits  Traits controlled by a single gene typically produce one of two outcomes (either - or)  Most behavioral and psychological traits are more complex  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  Twin studies  Comparison of monozygotic twins (identical and from the same fertilized egg) and dizygotic twins (fraternal and from different eggs).  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

 Adoption studies  Comparing adopted children alongside their biological parents and their adoptive parents.  Studying DNA  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. - A specific genotype does not always lead to the same phenotype. - Reaction range—range of potential phenotypes for a specific genotype. - Heritability estimate—extent to which genes are responsible for the differences among people; range from 0 to 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  Passive genotype  environment effects  Evocative genotype  environment effects  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  Prenatal Development  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)  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)  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 )  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  Sickle-cell desease  PKU  Huntington’s disease  Down syndrome  Klinefelter’s syndrome  Turner’s syndrome  XYY complement  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  Parents’ age  Nutrition  Stress  Disease  Drugs  Environmental hazards  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