Ch 2 Biological Foundations

natural selection

an evolutionary process by which individuals of a species that are best adapted are the ones that survive and leave the most fit offspring

adaptive behavior

behavior that promotes an organism’s survival in the natural habitat, because an organism possesses characteristics needed for survival

evolutionary psychology

emphasizes the importance of adaptation and reproduction to ensure survival

• offspring that adapts, develops behaviors, and possesses self-protective traits survive

true or false. psychological mechanisms are domain-specific

true

true or false evolutionary selection largely benefits the young

true. point is to survive long enough to bear children

what behaviors are most adaptive to survival?

behaviors that promote attachment, forming a group/culture, etc

what psychological traits were most adaptive for survival?

aggression in men, nurturing behavior in women

evaluation evolutionary psychology

criticisms:

• doesn’t adequately value social/environmental factors

• relies on after-the-fact explanations

• cannot be tested scientifically

true or false. evolution dictates behavior

false.

Bandura’s Social Cognitive Theory

• Acknowledges importance of evolution on human behavior

• Incorporates influence of society / culture

• Environment, biology, and culture influence one another

• We can change our environmental conditions over time (e.g., technology)

human genome project

mapped the human genome - the complete genetic content of our cells

• humans have only about 22,000 genes

Gene expression

affected by the environment. hormones in the blood can turn genes “on” and “off”

certain genes are turned on or off as a result of exercise, through methylation

• tiny molecules attach themselves to the outside of a gene, making the gene less capable of receiving and responding to biochemical signals from the body

• stress, exercise, nutrition, radiation, temperature, and lack of sleep can negatively influence gene expression

sources of variability

• mutated gene: a permanently altered segment of DNA

• susceptibility genes: genes that make the individual more vulnerable to specific diseases or accelerated aging

• longevity genes: genes that make the individual less vulnerable to certain diseases and more likely to life to an older age

down syndrome

a form of an intellectual disability caused by the presence of an extra copy of chromosome 21

klinefelter syndrome

a sex-linked chromosomal disease which males have an extra X chromosome, making them XXY instead of XY

• characteristics are underdeveloped testes, enlarges breasts, and becoming tall

fragile x syndrome (FXS)

a sex-linked disorder involving an abnormality in the X chromosome, which becomes constricted and often breaks

• Can cause intellectual disability, learning disability, or short attention span.

tuner syndrome

a sex-linked disorder in females in which either an X chromosome is missing or the second X chromosome is partially deleted

• Can cause intellectual disability and sexual underdevelopment.

XXY syndrome

a sex-linked disorder in which males have an extra Y chromosome

• Can cause above-average height.

what are gene-linked abnormalities caused by?

harmful genes

phenylketonuria(PKU)

a genetic disorder in which an individual cannot properly metabolize an amino acid called phenylalanine

sickle-cell anemia

a genetic disorder that affects the red blood cells and occurs most often in people of African descent

• Red blood cells become hook-shaped and cannot carry oxygen properly

tests which indicate whether a fetus is developing normally

• ultrasound sonography

• brain-imaging techniques

• chorionic villus sampling

• amniocentesis

• maternal blood screen and cell-free DNS

• noninvasive prenatal diagnosis (NIPD)

• fetal sex determination

in vitro fertilization (IVF)

a process in which eggs and sperm are combined in a laboratory dish by experts

• One or more of the resulting zygotes is transferred into the woman’s uterus.

• Multiple zygotes can increase health risks.

• IVF success rate depends on the mother’s age and other factors.

types of adoption

• Domestic adoption from the public welfare system

• Domestic infant adoption through private agencies and intermediaries.

• International adoption.

behavior genetics

the field that seeks to discover the influence of heredity and environment on individual differences in human traits, development, and behavior

twin study

the behavioral similarity of identical twins is compared with the behavioral similarity of fraternal twins

adoption study

seeks to discover whether behavioral and psychological characteristics of adopted children are more like those of their adoptive parents or biological parents.

• Adoptive parents provided the home environment.

• Biological parents contributed their heredity

adaptive behavior

those that enable a person to get along in their life or succeed in their environment

passive genotype-environment correlations

occur because biological parents provide a rearing environment for the child

evocative genotype-environment correlations

occur because a child’s genetically influenced characteristics elicit certain types of environments.

active (niche-picking) genotype-environment correlations

occur when children seek out environments that they find compatible and stimulating and suited for their genetically influenced abilities

epigenetic view

development is the result of an ongoing, bidirectional interchange between heredity and environment

gene x environment (G X E) interaction:

the interaction of a specific measured variation in the DNA and a specific measured aspect of the environment.