Question 1

John believes that Saturdays are more likely to be cloudy or rainy than weekdays are. However, he is relying entirely on casual impressions; he has never collected data systematically to test his hypothesis. His belief is most likely an example of

Accepted Answer

John's belief is an example of an illusory correlation, as he has formed a perceived relationship between two variables (Saturdays and weather) without any empirical evidence to support it.

Question 2

If an increase in one variable is not associated with any consistent increase or decrease in a second variable, then the correlation between the two variables is

Accepted Answer

When an increase in one variable is not associated with any consistent increase or decrease in a second variable, then there is no correlation between the two variables, meaning the correlation is zero.

Question 3

Parents who frequently beat their children tend to have aggressive children. What, if anything, can we conclude?

Accepted Answer

The statement only establishes a correlation between parents beating their children and the children being aggressive. It does not provide enough information to determine causation, genetic inheritance, or the direction of the relationship, thus we cannot conclusively draw any of the specific conclusions listed in options A, B, or C.

Question 4

What can we conclude if the correlation between variable A and variable B is zero?

Accepted Answer

If the correlation between variable A and variable B is zero, it means there is no linear relationship between the two variables. This does not necessarily mean that they have the same mean, median, or distribution (option A) or that one variable consistently goes up or down as the other variable changes (option D). It also does not mean that we can predict the value of B with zero error if we know the value of A (option C). Therefore, the best choice is B, which describes the lack of consistent direction in the relationship between the two variables.

Question 5

Researchers have found that people who report having trouble sleeping are more likely than others to become depressed. Which of the following conclusions, if any, follows from these data?

Accepted Answer

The data only shows a correlation between trouble sleeping and becoming depressed, not causation or the direction of the relationship, making none of the specific conclusions (A, B, C) directly supported by the data provided.

Question 6

Researchers report that people who smile frequently are more likely than other people to have many friends. Which of the following conclusions can we draw, if any?

Accepted Answer

The information provided does not allow us to definitively conclude that smiling causes one to have more friends (A), that a third factor influences both smiling and making friends (C), or that having friends causes one to smile more often (D). Therefore, we cannot draw any of these specific conclusions based on the information given.

Question 7

Researchers have found that people who own many books about chess tend to be better chess players than those who own few or none. This conclusion was almost certainly based on what kind of study?

Accepted Answer

The conclusion that people who own many books about chess tend to be better chess players than those who own few or none suggests a correlation between book ownership and chess playing ability. Therefore, the study is likely a correlation study. The other options - single-blind experiment, double-blind experiment, and case study - do not fit the context of the given conclusion.

Question 8

If the correlation between variables A and B is zero, then

Accepted Answer

A zero correlation between variables A and B means that there is no linear relationship between them. This does not necessarily mean that the relationship between the two variables is random, but rather that there is no systematic change in one variable as the other changes. It is possible that there may still be a nonlinear or other type of relationship between the two variables.

Question 9

Researchers have found that people who live in crowded cities are more likely than others to develop schizophrenia (a psychological disorder). From these results, which of the following conclusions (if any) can we draw?

Accepted Answer

The research findings only establish a correlation between living in crowded cities and a higher likelihood of developing schizophrenia, not a causal relationship. Therefore, we cannot definitively conclude that city life causes schizophrenia (A), that people with schizophrenia move to cities (B), or that those predisposed to schizophrenia choose city life (C) based solely on this correlation.

Question 10

The main reason for the persistence of many illusory correlations is the fact that

Accepted Answer

Illusory correlations persist because people selectively remember facts that support their expectations. This occurs because people are more likely to attend to and remember information that confirms their pre-existing beliefs or expectations. As a result, they may overlook or forget information that contradicts their beliefs, leading them to continue to perceive a correlation where none actually exists.

Question 11

An illusory correlation is

Accepted Answer

An illusory correlation is a perceived relationship between two variables that does not actually exist or is greatly exaggerated. It is an error in thinking or perception, rather than a true correlation between the variables themselves.

Question 12

Which of the following correlation coefficients indicates the weakest relationship between two variables? That is, which one permits the least accurate predictions of one variable from the other?

Accepted Answer

A correlation coefficient of 0 indicates no linear relationship between the variables, so predictions based on the correlation would be least accurate.

Question 13

If the correlation between variable A and variable B is +1, then

Accepted Answer

A correlation of +1 indicates a perfect positive relationship between two variables, meaning as one variable increases, the other variable also increases in a perfectly linear manner. However, correlation does not imply causation; it does not tell us whether one variable causes the other to change.

Question 14

Which of the following correlation coefficients indicates the strongest relationship between two variables? That is, which one would enable us to make the most accurate predictions of one variable from the other?

Accepted Answer

The correlation coefficient that indicates the strongest relationship between two variables is the one closest to -1 or +1. Therefore, the strongest relationship is indicated by a correlation coefficient of -0.9. This means that the two variables are very strongly negatively correlated, so that as one variable increases, the other decreases predictably. This would enable us to make the most accurate predictions of one variable from the other.

Question 15

Researchers find that happy people tend to be healthier than unhappy people. From this kind of information, which of the following (if any) can we conclude?

Accepted Answer

The information provided only establishes a correlation between happiness and health, not a causal relationship. Therefore, we cannot conclude that one causes the other or if there's a third factor influencing both.

Question 16

An investigator finds no consistent relationship between how much sleep students get at night and their grade point average in school. According to that study, the correlation between sleep and grades is

Accepted Answer

The statement "no consistent relationship" indicates that there is no correlation, thus the correlation coefficient would be zero.

Question 17

The correlation between A and B is +.60; the correlation between C and D is -.75. What do we know about causation based on the above?

Accepted Answer

Correlation does not imply causation. We cannot make any conclusions regarding causation based solely on information about correlations.

Question 18

One reason why illusory correlations arise and persist is that

Accepted Answer

Illusory correlations occur when people perceive a relationship between two variables, even when there is no actual relationship. This can be due to cognitive biases such as confirmation bias, where people tend to search for and remember information that confirms their existing beliefs or expectations. As a result, people may remember and give more weight to examples that fit their expectations and overlook those that do not, leading to the persistence of illusory correlations.

Question 19

Some people believe that genius is associated with insanity, although they have no scientific evidence to support their claim. This is an example of

Accepted Answer

This is an example of an illusory correlation, which is the perception of a relationship between two variables when in reality no such relationship exists. In this case, people may believe there is a relationship between genius and insanity based on anecdotal evidence or cultural stereotypes, rather than empirical research.

Question 20

An investigator finds that it is possible to use measurements of people's speed of response as a moderately accurate predictor of their grades in school. From this information we can conclude that the correlation between speed of response and grades is

Accepted Answer

Since the speed of response can predict grades with moderate accuracy, it indicates a relationship exists between the two variables, meaning the correlation is not zero. However, without specific directionality indicated (whether faster responses correlate with higher or lower grades), we cannot determine if the correlation is positive or negative, only that it is not zero.

Quiz 2: Scientific Methods in Psychology