AP Psych Unit 1.1

Interaction Of Heredity and Environment

The Nature-Nurture Issue

Nature Vs. Nurture: The old controversial question of Do our genes(Nature) our our environment/experiences(Nurture) develop and impact our psychological traits, human behaviors, and mental processes?

Heredity: passion on of different physical and mental traits from one generation to another

Our Genes come from our parents and are heredity and make up our biological DNA. They give us certain physical traits

As for nurture, its how the world around us shapes who we become. Things like culture, education, family interactions and life experiences in general are all environmental factors (because its outside our genes) that play a role in our personality, belief and behaviors as we grow.

Nature and Nurture: We know now that nature and nurture work together to determine our individual behaviors. Our genes and enivornment influence and interact with each other.

Genetic Predisposition: a tendency for certain traits to be inherited, including physical and mental conditions and disorders.

Evolutionary Perspective on Behavior

Natural Selection: the principle that inherited traits enabling an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.

Charles Darwin believed his theory not only applied to animal structures but also animal behaviors

Evolutionary Psychology: the study of of the evolution of behavior of the mind, using principles of natural selection. Genetics and environmental interact leading to changes in genetics to fit the environment. “how are we humans alike because of our shared biology and evolutionary history?”

Evolutionary Psychologists study what makes us alike as humans using natural selection because it helps explain our similarities.

Basically natural selection has shaped our behaviors and mental processes over time.

• behaviors that helped our ancestors survive and reproduce were most likely to be passed down.

Behavior Genetics: the study of the relative power and limits of genetic and environmetal limits on behavior. “How do we individually differ because of our differing genes and environments?”

behavior Genetics focuses on the human differences of genetic and environmetal roots.

Twin and Adoption Studies

To study how genes influence behavior and mental processes , researchers often use family-based studies.

Twin Studies: compare the similarities between identical twins and fraternal twins and to assess the relative conditions of heredity and environment to some degree on twins who have grown together and apart.

• if identical twins are more alike in trait than fraternal twins than it suggests a genetic influence.

Identical (monozygotic) twins: individuals who developed from a single fertilized egg that split into 2 and creating 2 genetically identical organisms

Fraternal (dizygotic) twins: individuals who developed from separate fertilized eggs that share a maternal prenatal environment but are no different than ordinary siblings.

Family Studies: research conducted among genetic relatives to look at how traits are shared among them.

• If a trait runs in families more than would be expected by chance, it may have a genetic basis

Adoption Studies: research conducted among environmental relatives that looks at the genetic and environmental factors in the development of personality and behavior by comparing the children with their biological parents and their adoptive parents.

• Similarities to biological relatives suggest genetic influences, while similarities to adoptive families point to environmental factors

Epigenetics

Epigenetics: “above” or “in addition to” (epi) genetics; the study of molecular mechanisms by which environments can influence or block genetic expression (without a DNA change)

• Genes are self regulating

• our experiences create epigenetic marks that attach to DNA strand

• that mark can instruct the cell to turn off a gene present in the DNA

• environmental factors can affect the epigenetic molecules

Our genes affect how people react to and influences us. Nature via nurture