Chapter 4

Behavior Genetics

- the study of the relative power and its limits of genetic and environmental influences on behavior

- study differences in humans and analyze the effects that genetics and heredity had on behavior and personality

Environment

- every non-genetic influence, from prenatal nutrition to the people and things around us

- anything else that can impact development that is not related to genetics

Chromosome

- a thread-like structure made of DNA molecules that contain genes

- 23 chromosomes from mom and 23 chromosomes from dad make up 46 chromosomes total

DNA

- deoxyribose nucleic acid

- a complex molecule containing the genetics information that makes up the chromosomes

- double stranded helix

Genes

- biochemical units of heredity that make up the chromosomes

- segments of DNA capable of synthesizing proteins

- small segments of DNA molecules

- the average person has about 20,000 to 25,000 genes

Genome

- the complete instructions for making an organism

- contains all the genetic material in that organism's chromosomes

- all the genes for a species

Identical Twins

- monozygotic twins

- develop from a single fertilized egg that splits into two, creating two genetically identical twins

- although they have the same genes, they don't always have the same copies of those genes

- most times they share a placenta in the womb

Fraternal Twins

- dizygotic twins

- twins that develop from two separate eggs

- genetically no closer than ordinary siblings, but share a prenatal environment

Temperament

- a person's characteristic emotional reactivity and intensity

- quickly apparent and genetically influenced

- "easy" vs "hard" newborns

Heritability

- the proportion of variation among individuals that we can attribute to genes

- heritability of a trait may vary, depending on the range of populations and environments studied

- ex. the heritability of general intelligence is 66%, meaning that genetic influence explains about 66% of observed variation among people

- 100% heritability: differences in people who are raised in the exact same environment with the exact same experiences

Molecular Genetics

- the subfield of biology that studies the molecular structure and function of genes

- explores how variations in genes lead to different traits in people

Molecular Behavior Genetics

- the study of how structure and function of genes interact with our environment to influence behavior

- the goal is to find the genes that orchestrate complex traits such as sexual orientation and heritability

Epigenetics

- the study of environmental influences on gene expression that can occur without a DNA change

- "in addition to genes" or "above and beyond" genetics

Evolutionary Psychology

- the study of the evolution of behavior and the mind, using principles of natural selection

- focus on what makes us so much alike as humans

Natural Selection

- the principle that nature selects the traits that allows for greatest success to be passed on to offspring

- organisms' varied offspring compete for survival

- certain biological and behavioral variations increase organisms' reproductive and survival chances in their particular environment

- offspring that survive are more likely to pass on their genes to ensuing populations

- thus, over time, population characteristics may change

Mutation

- a random error in gene replication that leads to a change in the trait and the trait it codes for

- gene mutations cause population characteristics to change and evolve over time

Social Script

- culturally modeled guide for how to act in various situations

- women might be wary of unknown men because they could be rapists or something

- others question the idea that the response is hard-wired --> "boys will be boys"

- evolutionary psychologists agree that we are not "hard-wired" and we have evolved to be adaptable

Interaction

- the interplay that occurs when the effect of one factor(like environment) depends on another(like heritability)

- nature via nurture

- neither heredity nor experience acts alone: environments trigger gene activity

Culture

- the behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next

- "culture is a better way of being social"

- culture enables efficient division of labor

Norm

- an understood rule for accepted and expected behavior

- prescribe "proper" behavior

- different norms in different cultures

- ex. Asians only eat with the right hand, British people will always wait in line or wait for their turn

Individualism

- independent sense of "me"

- aware of unique personal convictions and values

- higher priority to personal goals

- strive for personal control and individual achievement

- more prominent in Western cultures

Collectivism

- group identification: sense of belonging, set of values, and assurance in security

- deeper, most stable attachments to group

- team victory over performance

- value humility

- "we" not "me"

- defined by social networks

Sex

- in psychology, the biologically influenced characteristics by which people define males and females

- determined by chromosomes and anatomy

Gender

- in psychology, the socially influenced characteristics by which people define men and women

- shaped by culture's expectations

Aggression

- any physical or verbal behavior intended to harm someone physically or emotionally

- done intentionally

Relational Agression

- an act of aggression(physical or verbal) intended to harm a person's relationship or social standing

- ex. bullying someone to make them fall to the bottom of the social ladder

X Chromosome

- the sex chromosome found in both men and women

- females have two x chromosomes, males have one

- an x chromosome from each parents produces a female child

Y Chromosome

- the sex chromosome only found in males

- when paired with an x chromosome from the mother, it produces a male child

Testosterone

- the most important of male sex hormones

- both males and females have it but additional testosterone in males stimulates growth of male sex organs and characteristics

Puberty

- the period of sexual maturation, when a person becomes capable of reproducing

- girls enter puberty earlier than boys, and for a little bit, are taller than boys of the same age

Primary Sex Characteristics

- the body structures(ovaries, testes, and external genitalia) that make sexual reproduction possible

- develop during puberty

Secondary Sex Characteristics

- non-reproductive sexual traits

- ex. female breasts and hips, male voice quality and body hair

Spermarche

- puberty's landmark for boys

- "wet dream"

- first ejaculation

Menarche

- puberty's landmark in girls

- first period

Disorder of Sexual Development

- an inherited condition that involves unusual development of sex chromosomes and anatomy

- can happen if a fetus is exposed to unusual levels of sex hormones

Role

- a set of expectations(norms) about a social position

- define how those in a position ought to behave

Gender Role

- a series of expected behaviors, attitudes, and traits for males or for females

- ex. women should be housewives and men should work

Gender Identity

- our sense of being male, female, or a combination of both

- ex. a transgender man was born a female but has the gender identity of a woman

Social Learning Theory

- the theory that we learn social behavior by observing and imitating others and by being rewarded or punished

- ex. you might start smoking just because all of your friends smoke

Gender Typing

- the acquisition of a traditional masculine or feminine form

- no matter how much parents encourage traditional gender roles, children drift towards what they like

Androgyny

- displaying both traditional masculine and feminine psychological characteristics

- androgynous people are more adaptable and show greater flexibility in behavior and career

Transgender

- an umbrella term describing people whose gender identity or expression differs from that associated with their birth sex

- a heterosexual transgender person is attracted to people of the opposite birth sex

Personalities

- the unique and enduring patterns of thoughts, feelings, and behaviors that characterize an individual

- shaped by genetic predispositions and environmental experiences

- influences how people think, feel, and interact with the world

Male Answer Syndrome

- the tendency of men to provide an answer, even if they don't know the right one

- interrupt or preempt others in a conversation

- mansplaining

Self-Regulating Genes

- genes that react to environmental factors

- don't act like other genes that give the same exact result no matter what

- ex. butterfly wings change color depending on the season

Gender Schema Theory

- proposed by Sandra Bem

- suggests that children develop mental frameworks, or schemas, to organize information about gender roles and expectations

Gene Complexes

- a group of genes that work together in a functional unit, rather than being individual units

- ex. lac operon in bacteria

Family Self

- the development of an individual's sense of self within the context of their family, and how that sense of self is influenced by family relationships, dynamics, and interactions

- explores how individuals' sense of self is shaped and influenced by their family systems and relationships