. Payne (2001) gave participants a computerized task in which they first see a
face and then a picture of either a gun or a tool. The task was to press one button
if it was a tool and a different one if it was a gun. Unknown to the participants
while they were doing the study, the faces served as a “prime” (something that
starts you thinking a particular way); half the time they were of a black person
and half the time of a white person. Table 2–9 shows the means and standard deviations
for reaction times (the time to decide if the picture is of a gun or a tool)
after either a black or white prime. (In Experiment 2, participants were told to decide as fast as possible.) Explain the results to a person who has never had a course in statistics. (Be sure to explain some specific numbers as well as the general principle of the mean and standard deviation
In this study conducted by Payne in 2001, participants were given a computerized task where they first saw a face and then a picture of either a gun or a tool. The objective of the task was for the participants to press one button if the picture showed a tool and a different button if it showed a gun.
However, there was an additional factor at play that the participants were unaware of during the study. The faces shown before the pictures of the gun or tool were actually serving as "primes." A prime is something that triggers or influences our thinking in a particular way. In this case, the primes were either of a black person or a white person. Half the time, the participants were primed with a black face, and the other half of the time, they were primed with a white face.
The researchers recorded the participants' reaction times, which is the amount of time it took them to decide whether the picture showed a gun or a tool. These reaction times were then used to calculate the means and standard deviations for each condition, which are shown in Table 2-9.
Now, let's focus on the specific numbers in the table. The mean represents the average reaction time for each condition. In this case, we have two conditions: one with a black prime and one with a white prime. The mean reaction time after a black prime is 678 milliseconds (ms), while the mean reaction time after a white prime is 541 ms.
The standard deviation, on the other hand, quantifies the variability or spread of the reaction times within each condition. For the black prime condition, the standard deviation is 72 ms, and for the white prime condition, it is 59 ms.
To understand the general principle of mean and standard deviation, think of the mean as a measure of central tendency, indicating the average value. It gives us an idea of what the typical reaction time is in each condition. The standard deviation, on the other hand, provides information about the dispersion or spread of reaction times around the mean. A smaller standard deviation suggests that the reaction times are more consistent or clustered closely around the mean, whereas a larger standard deviation indicates more variability or scattered reaction times.
In summary, the results of this study showed that participants had longer mean reaction times when primed with a black face compared to when they were primed with a white face. Additionally, the standard deviations indicate that the reaction times in both conditions varied, but the variability was slightly higher in the black prime condition.