A research article, “Power Posing: Brief Nonverbal Displays Aff ect Neuroendocrine Levels and Risk Tolerance,” published in Psychological Science, September 2010, describes a study involving 42 volunteer participants (male and female), where participants were randomly assigned to hold either low power poses (contractive positions, closed limbs) or high-power poses (expansive positions, open limbs) for two minutes. All participants were told that the aim of this exercise was to see if their heart rate changed. Aft er the exercise, each participant was given $2 and told that they could keep the money or roll a die for a double or nothing. Of the 20 participants who held low-power poses, 3 took the “double or nothing” bet, whereas of the 22 participants who held high-power poses, 18 took the bet. Suppose we want to know, Are people who hold high-power poses more likely to take risks (such as the double or nothing bet) compared to those who hold low-power poses?
a. Was this an observational study or an experiment? How are you deciding?
b. What are the observational units?
c. What are the variables recorded? For each variable, identify the type of the variable (categorical or quantitative) and the role of the variable (explanatory or response).
d. Did the study involve random sampling, random assignment, or both? How are you deciding?
e. An appropriate analysis of the data shows that there is strong evidence that people in the high-power poses are more likely to take the double or nothing bet. Is it appropriate to conclude that the pose affects likelihood of taking the bet? Why or why not? Explain your reasoning.