Chapter 2

Biological and Environmental Foundations

Genetic Foundations• Chromosomes – store

and transmit genetic information.

• Genes – segments of DNA located along the chromosomes

• DNA – substance of which genes and chromosomes are made.

DNA’s Ladderlike Structure

Meiosis

Twins

Fraternal/Dizogotic• Two zygotes, or fertilized ova

Identical/Monozygotic

• One zygote that divides into two individuals

Dominant-Recessive Inheritance

X-Linked Inheritance

Genetic Imprinting and Mutation

Imprinting

• Chemical marker that activates either father’s or mother’s gene.

• Often temporary.

Mutation

• Sudden, permanent change in a DNA segment.

Chromosomal Abnormalities

• Down Syndrome- – results from

problems with the 21st chromosome.

• Sex chromosome Abnormalities- – problems with the X

or Y chromosomes.

Chromosomal Abnormalities --Down Syndrome

Prenatal Diagnostic Methods

• Amniocentesis 羊水诊断• Chorionic villus sampling

绒毛标本检查

• Fetoscopy 用胎儿镜观察胎儿• Ultrasound 　Ｂ超• Maternal Blood Analysis• Preimplantation

Fetal Medicine• Drugs delivered into u

terus• Surgery• Bone marrow transpl

ants 骨髓移植

• Genetic engineering and gene therapy

Reproductive Technologies

• Donor Insemination

• In Vitro Fertilization

• Surrogate Mother• 代孕母亲

• New Technologies

Adoption and Adjustment

Environmental Contexts

for Development

• Family• Socioeconomic

Status• Neighborhoods• Towns and Cities• Cultural Context

Family Influences on Development

• Direct– Two-person

relationships

• Indirect– Third Parties

• Adapting to Change– Changes from within

and outside the family

Socioeconomic Status and Family Functioning• Timing of Family Life

Cycle• Values and Expectations• Father’s Involvement• Communication and

Discipline Styles• Children’s Cognitive

Development

Individualist and Collectivist Societies

Individualist

• People think of themselves as separate from other people.

• Concerned with personal goals.

Collectivist

• People define themselves as part of a group.

• Concerned with group goals over individual goals.

How Much Does Heredity

Contribute to Behavior?Heritability

Estimates

• Portion of individual differences attributable to genetics.

• Ranges from 0 to 1.00.

Concordance

• What percent of the time do twins both show a trait?

• Ranges from 0 to 100%.

Reaction Range

Genetic-Environment Correlation

• Passive Correlation

• Evocative Correlation

• Active Correlation– Niche-picking

Contributions of Environment and Genetics

The Epigenetic 渐成的 Framework