PSYC 206 Lifespan Development Bilge Yagmurlu

I. Inheriting Culture Culture: The use of material and symbolic tools that accumulate over time, are passed on through social processes, and provide resources for the developing child.

The Tools of Culture Material tools: Includes physical manufactured objects and observable patterns of behavior

Tools of Culture Symbolic tools: More abstract, including systems of knowledge, beliefs, and values.

Process of Cultural Inheritance Culture is inherited through social processes Use of culture’s tools Social enhancement Imitation Explicit instruction

Process of Cultural Inheritance Culture is inherited through social processes. Use of symbolic communication Unique to humans Learning about things not immediately present and about abstractions

Complexity of Culture Cumulative Cultural Evolution Cultures continue to evolve because they are complex. Examples of Variations in tool usage Material Tools Symbolic Tools

Biological Evolution Heredity Transmission of biological characteristics from one generation to the next

Biological Evolution Genes: Genotype: Phenotype: Contains instructions that guide the formation of the individual’s traits Genotype: The exact genetic makeup Phenotype: The observable trait, behavior, and psychological traits

Natural Selection The process whereby individuals with phenotypes well adapted to the local environment survive and reproduce to a greater extent than individuals with less well- adapted phenotypes, preferentially passing on the genotypes associated with the better-adapted phenotypes.

Natural Selection Examples: Genotypic variations contribute to phenotypic contributions Baby-talk

Heritability The proportion of phenotypic (observed) variance in a given population that is due to genetic variance. Example: H of 20 = 20% GV and 80% Environmental

Plasticity of the Trait Phenotypic plasticity The degree to which the phenotype is open to influence by the environment, rather than by genotype. Traits with high plasticity Traits with little plasticity Example

Plasticity of the Trait Phenotypic canalization A trait is called “canalized” when it follows a strictly defined path, regardless of most environmental and genetic variations. Example:

Plasticity of the Trait Phenotypic canalization “auto-regulatory mechanism” 15

Heritability Assessed through kinship studies: Behavioral Genetics Methods Family Studies Twin Studies Adoption Studies

Genetic Inheritance Chromosome Ovum contains 23 Sperm contains 23 Zygote contains 46 or 23 pairs

Genetic Inheritance Chromosomes containing DNA (deoxyribonucleic acid) are situated in the nucleus of a cell. Genes are functional units of heredity which are composed of DNA.

Human Genome Project Genome is the set of complete instructions for making an organism, containing all the genes in that organism Completed in 2003, the HGP was a 13-year project coordinated by the U.S. with contributions from UK, Japan, France, Germany, China, etc. Some goals: identify all the approximately 20,000-25,000 genes in human DNA transfer related technologies to the private sector address the ethical, legal, and social issues (ELSI) that may arise 20

Heritability Assessed through kinship studies: Family Studies: Studies that correlate degree of genetic overlap among family members with degree of similarity in developmental outcomes

Heritability Family Studies Example: a disorder might be described as “running in a family” if more than one person in the family has the condition Example: “Anxiety disorders run in families”: role of inheritance and environment 22

Heritability: Twin Studies Identical twins Fraternal Same sex only Same or opposite sex Identical Twins develop from a single fertilized egg that splits in two, creating two genetically identical organisms Fraternal Twins develop from separate eggs genetically no closer than brothers and sisters 23

Heritability Twin Studies: Monozygotic Twins (100% shared genes) Dizygotic Twins (50% shared genes) If identical twins are more alike than fraternal twins, then the increased similarity can be due to genetic influences Relies on the “equal environments assumption” 24

Heritability Twin Studies: Equal environments assumption 25

Phenomena of Niche Construction: Refers to how behaviors, activities, and choices of individuals actively shape and modify the environment in which they live 26

Heritability Adoption Studies: Examine the correlations between adopted children and their adoptive parents, or adopted children and their genetic parents 27

Adopted / Separated Twins Investigators have also studied identical twins who were separated early in life and reared apart. Any similarities in traits between them should be primarily genetic and should permit a direct estimate of heritability. 28

III. The Coevolution of Culture and Biology the process that emerges from the interaction of biological evolution and cultural evolution.

III. The Coevolution of Culture and Biology Example The skeletal structure of humans and other primates are highly similar. But there are two main differences that might have caused early humans to develop high technology: 1) bipedalism 2) using thumb in opposition with the other four fingers 30