Objective 10/12/16 Provided notes, SWBAT evaluate the role genetics plays in determining behavior. Agenda: -Do Now: what makes you who you are? -Notes: genetics -Review

Do Now: 10/12/16 Read the article on genetics Once you have read, write a brief summary on your thoughts about what you have read (be ready to share) You may also include what you believe makes us who we are.

Introductory Psychology: Biological Bases of Behavior AP psychology: Unit II Topic: Behavior Genetics “We share half of our genes with a banana…” – Robert May

What is Behavior Genetics? The study of the relative power & limits of genetics and environmental influences on behavior Nature v. nurture

The Biological Bases: Basic Genetic Principles Part one

Basics: Genes – Our Code for Life Chromosomes Strands of DNA (deoxyribonucleic acid) that carry genetic information; located in the nucleus of every human cell Humans: 46 chromosomes (23/23) Genes DNA segments; key functional units in hereditary transmission Can be active (expressed) or inactive Sex Chromosomes Autosomes

Basics: Genes – Our Code for Life Like chromosomes, genes operate in pairs, with one gene in each pair coming from each parent Homozygous Condition Paired genes are the same Heterozygous Condition Paired genes are different In this case, one gene in the pair masks the other

Basics: Genes – Our Code for Life Genotype A person’s genetic makeup; determined at conception and fixed forever Phenotype The ways in which a person’s genotype is manifested in observable characteristics; may change over time **Different genotypes can yield the same phenotype **Genes are pliable Polygenic Inheritance Characteristics that are influenced by more than one pair of genes

Basics: Genes – Our Code for Life Genetic & Chromosomal Problems Cystic Fibrosis Two recessive genes; respiratory & digestive tract Sickle Cell Anemia Two recessive genes; blood disorder Tay-Sachs Disorder Two recessive genes; fatal neurological disorder Phenylketonuria Two recessive genes; difficulty digesting a certain amino acid – phenylalanine

Basics: Genes – Our Code for Life Genetic & Chromosomal Problems Down Syndrome Extra chromosome (21st pair) Klinefelter’s Syndrome Extra X chromosome; reduced masculine characteristics (e.g. enlarged breasts, obesity, etc.) Turner’s Syndrome Missing X chromosome (e.g. infertility, sexually underdeveloped, etc.)

The Biological Bases: Heritability Part two The ultimate nature-versus-nurture laboratory

What is Heritability? The extent to which the differences among people are attributable to their differing genes What percentage of the difference among height can be attributed to genes? 90% Individual differences v. group differences? Nature v. Nurture?

Heritability: Twin Studies Monozygotic Dizygotic

Heritability: Twin Studies Used to determine the heritability of a trait

Heritability: Jim Lewis Middle class Wife: Betty Son: James Alan Dog: Toy Hobby: Woodworking Bad Habits: Chain smoker, fingernail biter… Other: Drove a Chevy, watched stock-car racing & drank Miller… Conditions: High blood pressure & migraines…

Heritability: Jim Springer In 1980, Jim Springer called Jim Lewis (37 year separation) Everything down to their dog’s name was the same (except sons James Allan & James Alan) When listening to each other's voices, they would mistake themselves for the other First in Thomas Bouchard’s “Minnesota Twin Study”

Heritability: Adoption Studies Compare children's’ traits with those of their biological and adopted parents Studies suggest that adoptees tend to be more similar to their biological parents Two adopted children in the same household bear no more resemblance to each other than two biological siblings (in terms of personality)

Heritability: Adoption Studies S0 does parenting even have an effect? YES! It has an effect on biologically related and unrelated children alike Effects attitudes, values, manners, beliefs, faith, etc. Different from personality… “Heredity deals the cards, environment plays the hand…”

The Biological Bases: Molecular Genetics Part three DEFINITION: A branch extension of behavior genetics that asks the question, “Do specific genes influence behavior?” GOAL: To find some of the many genes that influence normal human traits (e.g. body weight, sexual orientation, extraversion)