Question 1

According to researchers, how much of the variation in personality traits among people in personality traits is likely due to genetics?

Accepted Answer

Research suggests that approximately 50% of the variation in personality traits among individuals is attributable to genetic factors. This estimate comes from studies of twins and families which show that genetics play a significant role in shaping our personality, alongside environmental factors.

Question 2

Growing up in the same household with the same parents has __________.

Accepted Answer

While growing up in the same household can have some influence on a person's degree of agreeableness, it is not the only factor. Other factors such as individual experiences, peer interactions, and genetics can also play a role. Therefore, the influence is considered mild.

Question 3

Wilhelm scores above average on extraversion and agreeableness. His identical twin Matteus, who was raised by a different family, has about a __________ chance of also scoring high on those same two traits.

Accepted Answer

Identical twins share 100% of their DNA, so their personality traits are highly influenced by genetics. Studies have shown that the heritability of extraversion and agreeableness is around 40-60%. Therefore, Matteus has a 67% chance of also scoring high on those same two traits, as these traits are influenced both by genetics and environmental factors.

Question 4

Which of these factors has the least amount of influence on personality development?

Accepted Answer

While all factors listed can have some influence on personality development, research suggests that shared environment (such as growing up in the same home or attending the same school) has the least impact compared to genetics, individual experiences, and friends.

Question 5

Jukka does not like to plan but loves to take risks. He is always seeking new experiences that heighten his senses. Jukka is likely high in __________.

Accepted Answer

Jukka's behavior of seeking new experiences and taking risks suggests that he is impulsive.

Question 6

Sir Francis Galton was an early pioneer in the study of twins. When he studied twin pairs, he asked them to identify other twins who might want to participate in his research. This technique is called __________.

Accepted Answer

The technique described is snowball sampling, as Galton asked initial participants to identify others who might be interested in participating. Random assignment involves randomly assigning participants to different groups or conditions, and convenience sampling involves simply sampling whoever is available or convenient. The ripple effect refers to a phenomenon where interventions or treatments spread beyond those directly involved, and is not relevant to this scenario.

Question 7

Why would a shared environment have such little effect on personality development?

Accepted Answer

Even in a shared environment, individuals have different perceptions and reactions to experiences, so the environment may not have a uniform effect on personality development.

Question 8

What is the most common research method for answering the "nature-versus-nurture" question about the contributions of genetics and the environment to personality development?

Accepted Answer

A twin study involves comparing the similarities of identical twins (who share 100% of their genes) and fraternal twins (who share an average of 50% of their genes) to determine the relative contributions of genetics and the environment to a particular trait, such as personality. This method allows researchers to estimate the heritability (proportion of variance in a trait that can be attributed to genetics) of a trait, and is widely considered the best method for studying the nature-versus-nurture question in psychology.

Question 9

__________ is another term for identical twins.

Accepted Answer

Monozygotic twins are also known as identical twins, as they originate from a single fertilized egg that splits into two embryos. Choice A, matched twins, is not a commonly used term for twins. Choice B, dizygotic twins, refers to fraternal twins, who originate from two separate fertilized eggs. Choice C, fraternal twins, is not synonymous with identical twins.

Question 10

Which term is used to refer to siblings growing up in the same household with the same parents?

Accepted Answer

Shared environment refers to the experiences, resources, and relationships that siblings share as a result of growing up in the same household with the same parents.

Question 11

Based on findings from twin studies, which of your family members is likely to have personality characteristics most similar to yours?

Accepted Answer

Identical twins who were reared in different households typically have the most similar personality characteristics due to their genetic makeup. Fraternal twins also have a higher likelihood of similar personality traits, but living together could also result in more differences due to environmental factors. Younger or older siblings may share some personality traits but are less likely to have as high of a genetic similarity as identical twins.

Question 12

What does the phrase "percentage of variance" tell a researcher?

Accepted Answer

The phrase "percentage of variance" refers to the amount of variation among a group of people, or in other words, the amount of difference in the measure being studied among the participants. It tells the researcher how much variability exists in the data, which can be helpful in identifying patterns or relationships. It does not indicate anything about the genetic or environmental influences on the trait or variation within an individual.

Question 13

Growing up in the same household with the same parents has __________.

Accepted Answer

Research in psychology, particularly studies on twins and adopted children, has shown that the home environment has little to no effect on certain personality traits such as extraversion. These traits are more strongly influenced by genetics and individual experiences outside the family environment.

Question 14

Cali and Cari are identical twins. Their parents want to make sure they have a chance to develop their own individual personalities, so they enroll Cali in soccer and Cari in dance. This is a reflection of the twins' __________.

Accepted Answer

The fact that the twins' parents are enrolling them in different extracurricular activities suggests that they are trying to provide a unique and individualized environment for each twin to develop their personality. This falls under the category of nonshared environment, which refers to the unique experiences and environments that siblings experience separately from one another. The choice is not A because identical twins share the same genetic makeup. The choice is not B because the twins are still living in the same household and therefore share a lot of the same environmental influences. The choice is not D because inherited circumstances refers to things like socioeconomic status or family history of certain genetic disorders, which are not relevant to the situation described in the question.

Question 15

According to researchers, how much of the variation among people in personality traits is likely due to environmental factors?

Accepted Answer

Research suggests that about 50 percent of the variation in personality traits among individuals is attributable to environmental factors, with the other half being influenced by genetic factors.

Question 16

Biology is a term that includes everything that appears in the body and the __________, regardless of its origins.

Accepted Answer

The term "biology" refers to all physical structures and processes within the body, including the brain. The other options (nonshared environment, social circle, shared environment) are not directly related to the body's structures and processes.

Question 17

Genetics alone are responsible for __________.

Accepted Answer

Eye color is primarily determined by genetics, while weight, personality, and gray hair are influenced by both genetic and environmental factors.

Question 18

Of the 35 pairs of twins Sir Francis Galton studied, how many pairs did he find that had very similar personalities?

Accepted Answer

Sir Francis Galton, in his studies on twins, found that 16 pairs out of the 35 he studied had very similar personalities, highlighting the role of genetics in personality development.

Question 19

The terms genetics and biology are__________.

Accepted Answer

Genetics refers specifically to the study of genes and heredity, while biology encompasses a much broader range of topics including genetics, ecology, physiology, and more. Therefore, they are not interchangeable and refer to different areas of study.

Question 20

What are the three main influences considered by researchers who study the origins of personality?

Accepted Answer

Researchers who study the origins of personality typically consider three main influences: nonshared environment, shared environment, and genetics. Nonshared environment refers to experiences that are unique to the individual, such as birth order, life events, and personal relationships. Shared environment refers to experiences that are shared among siblings, such as parenting styles, household atmosphere, and family values. Genetics refers to inherited traits and characteristics, which may influence personality development. Parental, peer, and social influences may also play a role, but they are often mediated by these three main influences.

Quiz 4: Biological Underpinnings of Personality

According to researchers, how much of the variation in personality traits among people in personality traits is likely due to genetics?

Growing up in the same household with the same parents has __________.

Wilhelm scores above average on extraversion and agreeableness. His identical twin Matteus, who was raised by a different family, has about a __________ chance of also scoring high on those same two traits.

Which of these factors has the least amount of influence on personality development?

Jukka does not like to plan but loves to take risks. He is always seeking new experiences that heighten his senses. Jukka is likely high in __________.

Sir Francis Galton was an early pioneer in the study of twins. When he studied twin pairs, he asked them to identify other twins who might want to participate in his research. This technique is called __________.

Why would a shared environment have such little effect on personality development?

What is the most common research method for answering the "nature-versus-nurture" question about the contributions of genetics and the environment to personality development?

__________ is another term for identical twins.

Which term is used to refer to siblings growing up in the same household with the same parents?

Based on findings from twin studies, which of your family members is likely to have personality characteristics most similar to yours?

What does the phrase "percentage of variance" tell a researcher?

Growing up in the same household with the same parents has __________.

Cali and Cari are identical twins. Their parents want to make sure they have a chance to develop their own individual personalities, so they enroll Cali in soccer and Cari in dance. This is a reflection of the twins' __________.

According to researchers, how much of the variation among people in personality traits is likely due to environmental factors?

Biology is a term that includes everything that appears in the body and the __________, regardless of its origins.

Genetics alone are responsible for __________.

Of the 35 pairs of twins Sir Francis Galton studied, how many pairs did he find that had very similar personalities?

The terms genetics and biology are__________.

What are the three main influences considered by researchers who study the origins of personality?