Domain 1 – Scientific Inquiry
Lab Exercise 1: Replication
Replication involves the repeating of the essence of a study or experiment to determine if its
results can be reliably reproduced. In this lab exercise, students will replicate an experiment
involving the influence of disgust on moral judgment.
Rationale
Replication is an important concept in psychological science. Replication acts as a vital check on
the progress of science by investigating whether the results of a given study or experiment will
be found again by a different investigator with a different sample. If results do not replicate,
that raises concerns about the conduct of the original study and whether the observed effect
was an artifact of chance.
Replication increasingly interests psychologists, because scientists have failed to replicate the
results from many notable studies from the history of psychology. This has raised valuable and
difficult questions for psychological scientists about how to conduct good science and further
develop psychological knowledge.
Key Takeaways
This lab will help students to understand how replication works and what variables can influence
results to replicate or not.
Materials
Sweet drink*
Water
Bitter drink*
Experimenter and participant instructions sheets
Moral vignettes sheet
Participant Scoring Sheet
*The original study used Minute Maid Berry Punch for the sweet drink and Swedish Bitters for
the bitter drink. You may use these or substitute other beverages.
Method
This lab replicates the Eskine, Kacinik, and Prinz (2011) experiment A Bad Taste in the Mouth:
Gustatory Disgust Influences Moral Judgment. In this experiment, participants take a small drink
of their assigned beverage (sweet, bitter, or control conditions) and then read three moral
situations, assigning each a rating of moral wrongness, ranging from not at all morally wrong to
extremely morally wrong. Participants then take a second drink of their assigned beverage and
rate three more moral situations. Students will replicate this experiment to learn more about
operational definitions and the process of replication.
You have two options for how to administer this lab exercise:
Option 1
Divide your students into experimenters and participants. This can be done within or across
course sections. The experimenter students can make some decisions about how to conduct the
experiment – which drinks to use, whether to use the provided rating sheet or to create their
own Likert scale system, how much of the drink to give in each dose, and so on. This option may
give rise to fruitful discussions about operational definitions and how small changes in the
experimental design may influence the results.
It may be necessary to modify the Experimenter Instructions Sheet or the Participant Scoring
Sheet if the experimenters choose to change the method of the experiment.
Option 2
You assume the role of experimenter and all of your students (subject to consent) are the
participants. This option will allow more of your students to experience the effect, but all the
decisions about how to operationalize the replication will be up to you. Discussing how these
decisions affect the results with your students may be more difficult as a result.
It may be necessary to modify the Experimenter Instructions Sheet or the Participant Scoring
Sheet if you choose to change the method of the experiment.
In both options, students should be responsible for collecting and analyzing the data. After
calculating the mean rating for each condition of the experiment (sweet, bitter, and control),
students can compare these results to see if the mean response differs by condition. Can an
effect of the drink can be observed? If so, what is the effect? The original study found that
participants in the bitter condition rated the situations as more morally wrong (i.e., a higher
response mean) than those in the sweet and control conditions. Compare your replication
results to this original result.
Remember to conclude the experiment with a debriefing of all participants. The debriefing
should discuss the results of the study and answer any questions the participants have. All
participant data should remain private, so discussions of results should be anonymous.
Discussion
1. The original experiment found that participants in the bitter condition rated the
vignettes more harshly than participants in the control or sweet conditions. Did you find
the same results?
2. If your results agreed with the original finding, what does this mean about the finding? If
your results did not agree with the original finding, what does this mean about the
finding?
3. What influences may have caused any differences between your findings and the
original study’s findings? Why would these variables matter?
4. In order to more accurately replicate the original study, what additional information
would you need about their method? Why would it be useful?
5. Identify the elements of this experiment – independent variable, dependent variable,
population, and sample.
Experimenter Instructions Sheet
1. Give participants informed consent and let them elect whether to participate in the
research. They should review ingredient lists for the drinks to be used to check for
allergens.
2. Randomly assign participants to each of the three conditions – sweet drink, bitter drink,
and control (water).
3. Give participants the Participant Instructions Sheet and the Participant Scoring Sheet.
4. Instruct participants to drink the first 1tsp dose of their assigned drink, in one smooth
motion and in one swallow.
5. Instruct participants to read each of the first three moral vignettes and assign each a
rating. Hand out the first batch of three vignettes.
6. Instruct participants to drink the second 1tsp dose of their assigned drink, in one
smooth motion and in one swallow.
7. Instruct participants to read each of the final three moral vignettes and assign each a
rating. Hand out the second batch of three vignettes.
8. Convert ratings into percentages. Do this by measuring the distance of the slash from
the left end of the continuum line and then divide by the length of the line.
9. Calculate the mean rating of moral responses from participants in each condition of the
experiment (sweet, bitter, and control) and complete the table below. Calculate the
standard deviation of moral responses from participants in each condition.
10. Analyze these results. Graph the mean rating from each condition. Do the mean ratings
differ across conditions? If so, how?
Average Rating by Condition
Sweet Condition
Bitter Condition
Control
Standard Deviation by Condition
Sweet Condition
Bitter Condition
Control
Moral Vignette #1
Moral Vignette #2
Moral Vignette #3
Moral Vignette #4
Moral Vignette #5
Moral Vignette #6
All Vignettes
Standard Deviation
Participant Instructions Sheet
1. You are being asked to voluntarily participate in this research of your own free choice.
Please review the informed consent form and decide whether you wish to participate in
this experiment.
2. You will be asked to drink two small amounts of a beverage during this experiment.
Please make sure that you have reviewed the ingredient list and that you are not allergic
to any ingredients in this beverage.
3. Please drink your beverage in one smooth motion and in one swallow.
4. After drinking the beverage, please read the description of each vignette carefully.
Consider whether the vignette appears to you to be morally wrong, from not at all
morally wrong to extremely morally wrong.
5. Mark the degree of your impression by making a vertical slash at the point on the line
that you think reflects the vignette’s moral wrongness. For example, if your impression
is that the vignette is a little morally wrong and far from extremely morally wrong, you
would make a vertical slash close to the left side of the continuum.
6. You will take one drink, read and rate three situations, take the second drink, and read
and rate three more situations.
Moral Vignettes Sheet
Cut this sheet into two slips of paper, separating the first three vignettes from the second three
vignettes. These slips should be provided to participants immediately after drinking their
assigned beverages. Participants should receive them in counterbalanced order.
Moral Vignette 1
You see a woman swerving her car in order to intentionally run over a squirrel.
Moral Vignette 2
You see a student copying a classmate's answer sheet on a makeup final exam.
Moral Vignette 3
You see an employee at a morgue eating his pepperoni pizza off of a dead body.
Moral Vignette 4
You see a teacher giving a bad grade to a student just because he dislikes him.
Moral Vignette 5
You see a teacher hitting a student's hand with a ruler for falling asleep in class.
Moral Vignette 6
You see a teenage girl openly staring at a disfigured woman as she walks past.
Participant Scoring Sheet
Please mark a vertical slash at the point on the line that reflects your impression of the vignette.
Moral Vignette 1
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Moral Vignette 2
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Moral Vignette 3
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Moral Vignette 4
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Moral Vignette 5
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Moral Vignette 6
Not at all morally wrong
Extremely morally wrong
|‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐|
Alignment
APA Standard Area: Research Methods, Measurement, and Statistics
● 1.1 Describe the scientific method and its role in psychology.
● 1.2 Describe and compare a variety of quantitative (e.g., surveys, correlations,
experiments) and qualitative (e.g., interviews, narratives, focus groups) research
methods.
● 1.3 Define systematic procedures used to improve the validity of research findings, such
as external validity.
● 2.1 Identify ethical standards psychologists must address regarding research with
human participants.
● 3.1 Define descriptive statistics and explain how they are used by psychological
scientists
● 3.4 Interpret graphical representations of data as used in both quantitative and
qualitative methods
● 3.5 Explain other statistical concepts, such as statistical significance and effect size
● 3.6 Explain how validity and reliability of observations and measurements relate to data
analysis
Thinking About Psychology 4e Alignment
● Module 3 ‐ Research Strategies
● Module 4 ‐ Psychology’s Statistics
Sources:
Study Replicated:
Eskine, K.; Kacinik, N., & Prinz, J.J. (2011). A bad taste in the mouth: gustatory disgust influences
moral judgment. Psychological Science 22:295‐299. DOI: 10.1177/0956797611398497
Moral Vignettes:
Clifford, S., Iyengar, V., Cabeza, R., & Sinnott‐Armstrong, W. (2015). Moral foundations
vignettes: a standardized stimulus database of scenarios based on moral foundations
theory. Behavioral Research Methods. 47(4): 1178‐1198. DOI: 10.3758/s13428‐014‐0551‐2