Question 2

Type of feedback is the independent variable in the study.

In this study, researchers are primarily focused on how different types of feedback can influence the emotional states of mothers and, subsequently, affect their infants. Thus, the type of feedback serves as the independent variable.

A) Type of feedback

This option is correct because the type of feedback is manipulated by the researchers to observe its effects on mothers and infants. It directly impacts the emotional responses being studied, making it the independent variable in the context of affect contagion.

B) The topic of the speech

This option is incorrect as the topic of the speech does not pertain to the emotional feedback being studied. The researchers are not altering the topic but rather examining how feedback influences emotional states, which is not captured by this option.

C) Infants’ heart rates after being reunited with their mothers

This choice is incorrect because infants’ heart rates are a dependent variable that reflects the outcome of the study. The heart rates are measures taken after the manipulation of the independent variable (type of feedback) and do not influence the study's parameters.

D) Mothers’ heart rates after the task

This option is also incorrect as mothers’ heart rates serve as a dependent variable in the study, indicating the effects of the independent variable. While they provide relevant data, they do not represent the variable that is manipulated by the researchers.

E) Ages of mothers and infants

This option is incorrect because the ages of mothers and infants are demographic variables that remain constant throughout the study. They do not change as a result of the experimental manipulation and therefore cannot be considered an independent variable.

Conclusion

The independent variable in this study is the type of feedback, as it is the factor being manipulated to observe its effect on the emotional states of both mothers and infants. All other options either represent dependent variables or are irrelevant to the core experimental design, confirming that A is the only correct choice.