Manipulating an Independent Variable through Embodiment

Experimental Psychology

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Overview

Source: Laboratories of Gary Lewandowski, Dave Strohmetz, and Natalie Ciarocco—Monmouth University

In any experiment, the researcher attempts to manipulate participants in one group to have different thoughts, experiences, or feelings than the other groups in the study.  Some manipulations are overt, while others can be quite subtle. Embodiment is a growing research area focused on the theory that subtle physical experiences can unconsciously influence a person’s thoughts. For example if a person physically smiles, it often leads to elevated mood. That is, the physical experience of smiling changes the way a person feels.

This video uses a two-group experiment to see if the physical sensation of weight will lead people to be stricter by giving harsher forms of discipline to fellow students who violated campus policies. 

Cite this Video

JoVE Science Education Database. Experimental Psychology. Manipulating an Independent Variable through Embodiment. JoVE, Cambridge, MA, (2017).

Procedure

1. Define key variables.

  1. Create an operational definition (i.e., a clear description of exactly what a researcher means by a concept) of embodiment, or embodied cognition.
    1. For the purposes of this experiment, embodiment, or embodied cognition, involves the participant directly experiencing the physical sensation of weight in a non-obvious way that can unconsciously influence cognitions.
  2. Create an operational definition (i.e., a clear description of exactly what a researcher means by a concept) of discipline.
    1. For purposes of this experiment, discipline is defined as the severity of sanctions or punishment that a participant feels a fellow student should receive following a violation of campus policy (e.g., drinking underage).

2. Conducting the study

  1. Meet student/participant outside of the library.
  2. Provide participant with informed consent, a brief description of the research (getting students’ opinions on appropriate forms of discipline for campus conduct violations), a sense of the procedure, an indication of potential risks/benefits, the right of withdrawal at any time, and a manner to get help if they experience discomfort.
  3. Have the participant sign the informed consent form on researcher’s textbook in a way that the participant does not have to hold anything except the pen.
  4. Tell participant that you would like him/her to complete a written survey and to make the task easier, he/she can fill it out using a clipboard.
  5. The researcher should hand the participant the clipboard to hold, while the researcher takes 10 s to look for the proper survey in her bag. 
    1. Heavy clipboard has ~ 5 lb weight inside/attached.
  6. The researcher will then give the participant the survey and ask the participant to complete it (participant remains standing).
  7. The survey asks the participant to indicate her/his thoughts on the appropriate level of punishment for various campus infractions such as vandalism, plagiarism, or cheating on a test (Figure 1).
    Figure 1
    Figure 1: Sample student opinion survey given to participants.

3. Debrief.

  1. Participant is told the nature of the study.
    1. “Thank you for participating. In this study I was trying to determine if the experience of weight through holding something heavy would influence severity of discipline. There were two groups in the study, one group held a heavy clipboard, the other group held a standard clipboard. We hypothesized that those in the heavy clipboard condition would be stricter in their discipline by giving harsher penalties.”
    2. “We could not tell you about our hypotheses ahead of time because this process (what psychologists call embodied cognition) is an unconscious process that occurs outside of your awareness. Because of the nature of the deception, it is quite natural for participants to not realize that they were being deceived.”

4. Go through the “Conducting the study” procedure twice, with two different participants (one per condition). Once for a person completing the survey with a heavy clipboard, and once for a person completing it with a standard clipboard. The idea is that we are highlighting one participant per condition, but that in running a real version of the study there would be 61 per condition.

Embodiment is a growing research area focused on the theory that subtle physical experiences can unconsciously influence a person’s thoughts and feelings.

Embodiment, or embodied cognition, establishes the connection that bodily actions influence the mind, just as the mind influences actions.

For example, if a person manipulates facial muscles to form a smile, the motor action of smiling unintentionally leads to an elevated mood. That is, the physical experience of smiling changes the way a person feels.

This video will demonstrate how to setup and perform an experiment on embodiment, as well as how to analyze and interpret data investigating whether the physical sensation of weight influences thoughts about disciplinary actions for fellow students.

In this two-group experiment, half of the participants are unknowingly handed a standard clipboard, whereas the other half are unsuspectingly given a weighted clipboard.

While holding one of the clipboards, participants are asked to complete a survey regarding their thoughts on an appropriate level of discipline for various campus violations, which include: cheating on a test, underage drinking, excessive noise, and vandalism.

In this case, the dependent variable is the discipline level. There are five possible levels for each violation, ranging from a verbal warning to expulsion.

It is hypothesized that participants in the heavy clipboard condition will give harsher penalties than those handed the normal clipboard. For instance, a participant holding the heavy clipboard might feel that a student who causes excessive noise should be expelled from school.

Thus, the physical action of holding an object influences subsequent decision-making.

To begin the experiment, meet the participant at the lab.

Provide the participant with informed consent, a brief description of the research, a sense of the procedure, an indication of potential risks/benefits, and the right to withdrawal at any time.

Without the participant realizing it, hand them either a normal or heavy clipboard to hold and take 10 sec to look for the proper survey.

After searching for 10 sec, hand the survey to each participant and ask them to provide feedback regarding how students should be disciplined for campus violations.

After participants have completed and returned the survey, debrief them and explain why deception was necessary for the experiment.

To analyze how the action of holding different clipboards influenced disciplinary decisions, average the numbers from the discipline scale by condition and type of violation.

Graph the mean discipline levels and compare the conditions in each of the violations. After applying a t-test for independent means, notice that participants who held the heavy clipboard significantly gave stricter levels of discipline for six of the seven violations.

Now that you are familiar with how experimental psychologists demonstrate embodiment, let’s look at how other researchers manipulate the body to unknowingly influence the mind.

For example, researchers have used embodiment to study interpersonal relationships and mate selection. They found that participants who sat at a wobbly desk to answer questions sought romantic relationship partners who were more stable, reliable, and trustworthy.

In another study, researchers examined how the brain constructs body representations using a rubber hand illusion. Synchronous brushing of the rubber and hidden hand caused the participant to think that the rubber hand was in fact their hand.

By varying the tactile and visual stimuli, researchers determined what information was important to the brain for determining what a body part is.

You’ve just watched JoVE’s introduction to embodiment. Now you should have a good understanding of how to setup and perform an experiment, as well as analyze and assess the results.

Thanks for watching! 

Results

The data were collected from 122 participants. Recall that the discipline scale is calculated on the number assigned to each of the levels of discipline (e.g., 1 = verbal warning, etc.). To determine if there were differences between the heavy and light clipboard conditions on discipline levels, we performed a t-test for independent means.

The results indicated that participants who held the heavy clipboard gave stricter levels of discipline for 6 of the 7 violations (Figure 2). The only exception was for illegal downloading of copyrighted material, which did not demonstrate a significant difference between conditions. 

Figure 2
Figure 2: Discipline level for common violations by weight condition.

Applications and Summary

This two-group experiment shows how researchers can manipulate participants’ cognition in a subtle way that participants are not aware of through embodiment. 

This study replicates and extends previous research on embodiment by Jostman et al., which showed that holding a weighted clipboard made participants think that fair decision-making through listening to students’ opinions was more important.1 

Embodiment effects are increasingly popular and have been studied in a variety of contexts. For example, a recent study by Kille et al. in Psychological Science found that participants who sat at a wobbly desk (which the researchers created by sawing two of the legs short) sought romantic relationship partners who were more stable (i.e., reliable and trustworthy).2

References

  1. Jostmann, N. B., Lakens, D., & Schubert, T. W. Weight as an embodiment of importance. Psychological Science. 20(9), 1169-1174. doi:10.1111/j.1467-9280.2009.02426.x (2009).
  2. Kille, D. R., Forest, A. L., & Wood, J. V. Tall, dark, and stable: Embodiment motivates mate selection preferences. Psychological Science. 24(1), 112-114. doi:10.1177/0956797612457392 (2013).

1. Define key variables.

  1. Create an operational definition (i.e., a clear description of exactly what a researcher means by a concept) of embodiment, or embodied cognition.
    1. For the purposes of this experiment, embodiment, or embodied cognition, involves the participant directly experiencing the physical sensation of weight in a non-obvious way that can unconsciously influence cognitions.
  2. Create an operational definition (i.e., a clear description of exactly what a researcher means by a concept) of discipline.
    1. For purposes of this experiment, discipline is defined as the severity of sanctions or punishment that a participant feels a fellow student should receive following a violation of campus policy (e.g., drinking underage).

2. Conducting the study

  1. Meet student/participant outside of the library.
  2. Provide participant with informed consent, a brief description of the research (getting students’ opinions on appropriate forms of discipline for campus conduct violations), a sense of the procedure, an indication of potential risks/benefits, the right of withdrawal at any time, and a manner to get help if they experience discomfort.
  3. Have the participant sign the informed consent form on researcher’s textbook in a way that the participant does not have to hold anything except the pen.
  4. Tell participant that you would like him/her to complete a written survey and to make the task easier, he/she can fill it out using a clipboard.
  5. The researcher should hand the participant the clipboard to hold, while the researcher takes 10 s to look for the proper survey in her bag. 
    1. Heavy clipboard has ~ 5 lb weight inside/attached.
  6. The researcher will then give the participant the survey and ask the participant to complete it (participant remains standing).
  7. The survey asks the participant to indicate her/his thoughts on the appropriate level of punishment for various campus infractions such as vandalism, plagiarism, or cheating on a test (Figure 1).
    Figure 1
    Figure 1: Sample student opinion survey given to participants.

3. Debrief.

  1. Participant is told the nature of the study.
    1. “Thank you for participating. In this study I was trying to determine if the experience of weight through holding something heavy would influence severity of discipline. There were two groups in the study, one group held a heavy clipboard, the other group held a standard clipboard. We hypothesized that those in the heavy clipboard condition would be stricter in their discipline by giving harsher penalties.”
    2. “We could not tell you about our hypotheses ahead of time because this process (what psychologists call embodied cognition) is an unconscious process that occurs outside of your awareness. Because of the nature of the deception, it is quite natural for participants to not realize that they were being deceived.”

4. Go through the “Conducting the study” procedure twice, with two different participants (one per condition). Once for a person completing the survey with a heavy clipboard, and once for a person completing it with a standard clipboard. The idea is that we are highlighting one participant per condition, but that in running a real version of the study there would be 61 per condition.

Embodiment is a growing research area focused on the theory that subtle physical experiences can unconsciously influence a person’s thoughts and feelings.

Embodiment, or embodied cognition, establishes the connection that bodily actions influence the mind, just as the mind influences actions.

For example, if a person manipulates facial muscles to form a smile, the motor action of smiling unintentionally leads to an elevated mood. That is, the physical experience of smiling changes the way a person feels.

This video will demonstrate how to setup and perform an experiment on embodiment, as well as how to analyze and interpret data investigating whether the physical sensation of weight influences thoughts about disciplinary actions for fellow students.

In this two-group experiment, half of the participants are unknowingly handed a standard clipboard, whereas the other half are unsuspectingly given a weighted clipboard.

While holding one of the clipboards, participants are asked to complete a survey regarding their thoughts on an appropriate level of discipline for various campus violations, which include: cheating on a test, underage drinking, excessive noise, and vandalism.

In this case, the dependent variable is the discipline level. There are five possible levels for each violation, ranging from a verbal warning to expulsion.

It is hypothesized that participants in the heavy clipboard condition will give harsher penalties than those handed the normal clipboard. For instance, a participant holding the heavy clipboard might feel that a student who causes excessive noise should be expelled from school.

Thus, the physical action of holding an object influences subsequent decision-making.

To begin the experiment, meet the participant at the lab.

Provide the participant with informed consent, a brief description of the research, a sense of the procedure, an indication of potential risks/benefits, and the right to withdrawal at any time.

Without the participant realizing it, hand them either a normal or heavy clipboard to hold and take 10 sec to look for the proper survey.

After searching for 10 sec, hand the survey to each participant and ask them to provide feedback regarding how students should be disciplined for campus violations.

After participants have completed and returned the survey, debrief them and explain why deception was necessary for the experiment.

To analyze how the action of holding different clipboards influenced disciplinary decisions, average the numbers from the discipline scale by condition and type of violation.

Graph the mean discipline levels and compare the conditions in each of the violations. After applying a t-test for independent means, notice that participants who held the heavy clipboard significantly gave stricter levels of discipline for six of the seven violations.

Now that you are familiar with how experimental psychologists demonstrate embodiment, let’s look at how other researchers manipulate the body to unknowingly influence the mind.

For example, researchers have used embodiment to study interpersonal relationships and mate selection. They found that participants who sat at a wobbly desk to answer questions sought romantic relationship partners who were more stable, reliable, and trustworthy.

In another study, researchers examined how the brain constructs body representations using a rubber hand illusion. Synchronous brushing of the rubber and hidden hand caused the participant to think that the rubber hand was in fact their hand.

By varying the tactile and visual stimuli, researchers determined what information was important to the brain for determining what a body part is.

You’ve just watched JoVE’s introduction to embodiment. Now you should have a good understanding of how to setup and perform an experiment, as well as analyze and assess the results.

Thanks for watching! 

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