4.1 Behavior Genetics: Predicting Individual Differences

How do behavior geneticists explain our individual differences?

Behavior geneticists seek to quantify genetic and environmental influences on our traits. Shared family environments have little effect on personality, and the stability of temperament suggests a genetic predisposition.

Dr. Ramirez studies the effects of stress on pregnant mothers and how this stress may influence gender expression in their children. According to the biopsychosocial approach, Dr. Ramirez is studying the _____ influences on gender.

Biological

Maturation

Biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience

According to evolutionary psychologists, our predisposition to overconsume fatty junk foods illustrates that we are _____ to behave in ways that promoted the ________ of our ancestors.

Biologically prepared; surviva

Dr. Bryson is an evolutionary psychologist. She has suggested that people are genetically predisposed to:

Both fear dangerous animals and love their own children

Your sister has a 3-month-old baby girl who is always cheerful, relaxed, and predictable in terms of sleeping and eating. The baby's temperament is most likely that of a(n):

Easy Baby

Epigenetic's is the study of the molecule mechanisms by which _____ trigger or block genetic expression

Environments

Environmental factors such as diet, drugs, or stress can alter gene expression by affecting:

Epigenetic molecules.

Adaptation studies seek to understand genetic influences on personality. They do this mainly by?

Evaluating whether adopted children's personalities more closely resemble those of their adoptive parents or their biological parents

Environment.

Every nongenetic influence, from prenatal nutrition to the people and things around us

Two of the MOST unhealthy lifestyle factors of contemporary English-speaking countries are _____ and _____.

Insufficient sleep; long work hours

Nate was born with six fingers on his left hand. This illustrates:

Mutation

An understood rule for an accepted and expected behavior is called a(n) _____

Norm

The dramatic increase in Americans' premarital sexual activity over the past half century BEST illustrates that sexual behavior is influenced by:

Norms

The fact that many South Asians use only the right hand for eating demonstrates:

Norms

What is the stunning finding from studies of hundreds of adoptive families?

People who grow up together, biologically related or not, do not resemble one another in personality.

Epigenetics

"Above" or "In addiction to" (epi) genetics; the study of the molecular mechanisms by which environments can influence genetic expression (without DNA change)

Fraternal twins result when

2 eggs are fertilized by 2 sperm

Kolb and Whishaw (1998) found that after rats were housed for 60 days in enriched environments, the number of synapse connections in their brains had grown by about __________ percent

20%

Kolb and Whishaw (1998) found that after rats were housed for 60 days in enriched environments, the number of synapse connections in their brains had grown by about __________ percent.

20%

One of mothers egg and a father sperm unite, each contributions?

23 Chromosomes

Children demonstrate an understanding of gender roles by the age of:

3 Years Old

What percentage of sperm carries the X chromosome?

50%

DNA (deoxyribonucleic acid)

A complex molecule containing the genetic information that makes up the chromosomes.

When scientists compared the brains of rats raised in an enriched environment with the brains of rats raised in an impoverished environment, the rats raised in an enriched environment had:

A larger number of synapses.

Neuron

A nerve cell; the basic building block of the nervous system

A third-year PhD student explains to a newly admitted graduate student that "all the grad students here come in and work on both weekend days. It's the culture." The PhD student's statement BEST captures:

A norm.

John's family would always have a pasta dish on Sundays and only fish on Fridays. This is an example of:

A norm.

Temperament

A person's characteristic emotional reactivity and intensity

Dr. Vaughn is comparing brain scans from both men and women. He can expect to find:

A prenatal sex difference in brain network connections.

Chromosome

A threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins.

Identical (monozygotic) twins

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms

Of the following, who are likely to show greater genetic differences?

Two individuals from the same small village in Denmark

People all over the world react similarly when they are reunited with loved ones. For example, if you watch people greeting each other at family reunions, they tend to have the same joyful expressions on their faces, no matter what country they come from. This similarity can be attributed to:

People's shared human genome.

The average woman is different from the average man in which of the following ways?

She will live 4 years longer.

Teens who smoke typically have friends who smoke. To avoid overestimating the impact of peer pressure on teens, it would make the MOST sense to consider the impact of:

Smoking preferences on friendship choices.

Dr. Kim is interested in studying the differences in gender development in individualistic versus collectivistic cultures. According to the biopsychosocial approach, Dr. Kim is studying the _____ influences on gender.

Social-cultural

Heritability

The proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

What have psychologists learned about temperament?

The stability of temperament, a person's characteristic emotional reactivity and intensity, from the first weeks of life suggests a genetic predisposition. The genetic effect appears in physiological differences such as heart rate and nervous system reactivity.

Molecular Behavior Genetic

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

Behavior Geneticists

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

Molecular Genetics

The subfield of biology that studies the molecular structure and function of genes.

Donna was born as a genetic male with a typical XY chromosomal pattern. Her parents named her Timothy. She now feels she is a woman and lives as one. Donna is BEST described as:

Transgender.

Mark and Mike are twins who developed from a single fertilized egg. They are:

Same sex identical twins.

How is molecular genetics research changing our understanding of the effects of nature and nurture?

- Our genetic predispositions and our surrounding environments interact Environments can trigger gene activity, and genetically influenced traits can evoke responses from others. - Molecular geneticists study the molecular structure and function of genes, including those that affect behavior. - Psychologists and molecular geneticists are cooperating to identify specific genes-or more often, teams of genes-that put people at risk for disorders. - The field of epigenetics studies the influences on gene expression that occur without changes in DNA.

Our ability to react to the environment demonstrates our:

Adaptive capacity.

Jennifer is adopted, and Rebecca lives with her biological parents. It can be expected that the _____ will use gentler parenting, give more guidance, and experience less depression when compared to the _____.

Adoptive mother; biological mother

_____ parents are LEAST likely to influence the personality traits of their _____ children.

Adoptive; adopted

Interactions between the environment and heredity can result in differences in personality. Which of the following infants has genetically influenced traits (heredity) that might evoke responses in their caregivers (environment), which ultimately can influence personality characteristics?

All of these infant traits can influence both the caregiving environment and personality development

_____ is when a person is displaying both traditional masculine and feminine psychological characteristics.

Androgyny

The thread-like structures that contain genes are called:

Chromosome.

The threadlike structures made largely of DNA molecules are called

Chromosomes

Fraternal (dizygotic) twins

Develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment

Your professor suggests that the increasing problem of obesity in Western cultures might be attributable to our inherited predisposition to love the taste of sweets and fats. Although these foods were difficult for our ancestors to find, such foods helped them to survive famines. Now, these foods are easily available, and Westerners are eating too much of them. What field does this theory belong to?

Evolutionary Psychology

Research that uses principles of natural selection to examine changes in behavior and the mind would be of most interest to a(n):

Evolutionary psychologist

Using the principles of natural selection, _________________ studies how behavior and the mind have progressed

Evolutionary psychology

Men are _____ likely to suffer from alcoholism than women.

Four times as

Emily has adopted a traditional feminine role. This is called:

Gender typing.

A small segment of DNA that codes for a particular proteins is referred to as a

Gene

Put the following cell structures in order from smallest to largest: nucleus, gene, chromosomes

Gene, chromosomes, nucleus

Those studying the heritability of a trait try to determine how much of the person-to-person variation in that trait among members of a specific group is due to their differing

Genes

Compared to men, women ___________ risk for eating disorders.

Have a 10 times greater

_______ is the proportion of variation among individuals in groups that we can attribute to genes

Heritability

What is heritability and how does it relate to individuals and groups?

Heritability describes the extent to which variation among members of a group can be attributed to genes. Heritable individual differences (in traits such as height or intelligence) do not necessarily imply heritable group differences. Genes mostly explain why some people are taller than others, but not why people are taller today than they were a century ago.

___________ twins share the same DNA

Identical (monozygotic)

Which list pairs a type of culture with an accurate description?

Individualist - many casual relationships

Cho tends to take pride in his accomplishments and enjoy his privacy. His sister, Jen, stayed closer to their parents and her college friends. Unlike her brother, she felt a sense of belonging as a result. Cho is more likely to align himself with _____ values, while Jen prefers a(n) _____ emphasis.

Individualist; collectivist

Among humans, innovations in behavior and ideas are preserved and transmitted from one generation to another primarily through:

Language

Jake enjoys hunting, playing football, and wrestling, and Susan enjoys talking to her friends and taking care of her younger siblings. We can say that Jake is exhibiting traditionally _____ traits and that Susan is exhibiting traditionally _____ traits.

Masculine; Feminine

The finding that men are more likely than women to be sexually motivated applies to

Men in nearly all cultures.

In a study on aggression, a group of college students are given an experimental task intended to be purposely frustrating. Then the participants are given a task that forces them to administer (fake) electric shocks to another participant. Given what we know about gender differences and aggression, what should the research expect?

Men will administer more painful electric shocks.

Dr. Hakim is interested in studying aggression through research on how the structure and function of genes interact with our environment to influence aggression. Dr. Hakim works in the field of:

Molecular behavior genetics.

Professor Carlson aims to identify the specific genes that contribute to alcoholism. He is most likely a(n):

Molecular geneticist.

Jackie was exposed to excess testosterone during her prenatal development. As a young girl, Jackie is likely to:

Prefer a masculine play style.

Among humans, advances in behavior and ideas are maintained and transmitted from one generation to another primarily through:

Preservation of innovation.

National stereotypes, such as the idea that Canadians are polite or that Britons are reserved, are:

Real, but they reflect only small differences between people in different nations.

How do researchers use twin and adoption studies to learn about psychological principles?

Researchers use twin and adoption studies to understand how much variation among individuals is due to genetic makeup and how much to environmental factors. Some studies compare the traits and behaviors of identical twins (same genes) and fraternal twins (different genes, as in any two siblings). They also compare adopted children with their adoptive and biological parents. Some studies compare traits and behaviors of twins raised together or separately.

How do twin and adoption studies help us understand the effects and interactions of nature and nurture?

Studies of identical (monozygotic) twins versus fraternal (dizygotic) twins, separated twins, and biological versus adoptive relatives allow researchers to tease apart the influences of heredity and environment. Research studies on separated identical twins maintain the same genes while testing the effects of different home environments. Studies of adoptive families let researchers maintain the same home environment while studying the effects of genetic differences. Heritable individual differences (in traits such as height and weight) do not necessarily explain gender or ethnic group differences. Shared family environments have little effect on personality.

From the very first weeks of life, infants differ in their characteristic emotional reactions, with some infants being intense and anxious, while others are easy-going and relax. These differences are usually explained in differences in

Temperament

What is the "second Darwinian revolution"?

The application of evolutionary principles to psychology

According to Eagly and Wood, cultures with gender inequality are more likely to have _________________ than are cultures with gender equality.

The average woman is different from the average man in which of the following ways?

Genes

The biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein

You are in charge of hiring a cruise ship social director, and you want to pick someone who is very outgoing. Unfortunately, you only have information about the siblings of the candidates. Given what we know about the genetic transmission of outgoingness, which of the following candidates would you choose?

The candidate whose identical twin is outgoing.

Genome

The complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Heredity

The genetic transfer of characteristics from parents to offspring

Interact

The interplay the occurs when the effect of one factor (such as environment) depends on another factor (such as hereditary)

According to evolutionary psychologists, there are clear differences between male and female behaviors related to reproduction. Imagine a study in which an attractive woman approaches a man in a bar and starts a casual conversation with him. What will observers of this interaction think?

Unattached heterosexual men watching this scenario will perceive the woman's friendliness as sexual interest.

Your 17-year-old nephew seems to take a lot of risks compared to his 18-year-old sister. He drives faster than she does, he smokes cigarettes, and he has had several casual sexual partners. His sister does not want to have any kind of sexual relationship until she meets the right person. How would an evolutionary psychologist explain the difference between your niece and nephew?

Women are attracted to males who have the potential for long-term mating