Background

The purpose of the present study is to test the idea that people may sometimes make better decisions when they process the relevant information unconsciously, as opposed to consciously. Dijksterhuis, Bos, Nordgren, and van Baaren (2006) found that better decisions were made about complex choices if conscious thought was prevented and the unconscious was allowed to mull the options over. These findings were demonstrated both in the lab and in the field. This suggests that our intuitions might deserve more credit than we normally give them, in some situations.

Although this advantage of deliberation without attention has been replicated in several subsequent studies (Bos, Dijksterhuis & van Baaren, 2011; McMahon, Sparrow, Chatman, & Riddle, 2011), other research suggests that this effect is a very elusive one to try to replicate (Nieuwenstein, Wierenga, Morey, Wicherts, Blom, Wagenmakers, & van Rijn, 2015), and that there may be reliability and validity problems with much of the previous research that found an unconscious thought advantage.

The current study, carried out in our lab, is an attempt to demonstrate an unconscious thought advantage, using stimuli from McMahon et al. (2011). Subjects were required to choose the best candidate from three fictional students, Alex, Taylor and Morgan, based upon a list of academic attributes. Alex was the best candidate with 75% positive attributes, followed by Taylor with 50% positive attributes and finally Morgan with only 25% positive attributes. We will be comparing the ratings for Alex in the Unconscious versus Conscious thought conditions, to see if there is a significant difference in preferences for Alex in the two conditions. If there is an Unconscious thought advantage, then the Unconscious thought group should rate Alex differently than in the Conscious thought condition. We will also do a similar comparison of Morgan in the Unconscious and Conscious thought conditions. If there is an Unconscious thought advantage, then the Unconscious thought group should rate Morgan differently than in the Conscious thought condition.

The fact that there are large inconsistencies in the findings of the prior research affirms the need for further attempts at replication.

LAB REPORT - The lab report should follow correct APA style as presented in the APA Essentials document posted on Blackboard, and as specified in the 6th edition of the APA manual.

You will submit the lab report in two sections. The first will comprise the Title page, Introduction, Method, Reference and Appendix section. The second section, comprising the Title page, Abstract, Results, Discussion, References, and Appendix. Although you will be submitting the lab report in two parts, you should read this whole document to get an idea of the entire study, of what conditions will be compared, using which tests.

Sections of the Report:

Title Page: see APA Essentials and the 6th edition of the APA manual.

Abstract: The abstract is usually the last part of the lab report that you will write. Follow the guidelines provided in the above documents.

Introduction:
• Briefly, what is the purpose of our study?
• Review some of the relevant the prior literature on the unconscious thought advantage effect. Summarize Dijksterhuis et al. (2006) and McMahon et al. (2011). Links to these two papers are provided on BB. In addition, find two other relevant primary research articles and summarize them as well. At least one of these articles should have findings contrary to the above two papers. They must be as recent as 2007 and you must include a copy of their first pages in your Appendix (for Lab Report 1).
• Finally, you must briefly describe the current study. Clearly identify the independent and dependent variables, using operational definitions. Then, make two precise, testable predictions about the expected results of the t-tests for the current study, being sure to indicate the expected direction. What is the rationale for each of your predictions?

Be very, very careful to use your own words - do not copy from the published sources or from this handout. Although you may be tempted to quote (using appropriate APA quotation procedures) it is better that you do not quote at all because this does not demonstrate any understanding of the content - USE YOUR OWN WORDS.

Method: Describe the participants, materials, and procedure as required by APA format.
• Participants: There were a total of 40 participants, with 20 in each group.
• Materials: Refer to the actual stimuli on Blackboard in order to describe the stimuli for the different conditions. Be sure that the differences between the stimuli sets is very clear, and include an APA citation for McMahon et al. (2011) for the stimuli.
• Procedure: Describe what a typical subject was exposed to, clarifying differences in conditions, and specifying exact time intervals.

Results: In the results, you will first present the descriptive statistics and then the results of the
t-tests conducted to test our predictions.
• Present the 6 means and standard deviations in an APA table.
• Draw a bar graph of the above means
• Comment on the values in the table and the graph. What effects are they showing, if any?
• As will be demonstrated in lab, using R, perform an appropriate t-test to determine whether there is a significant difference between the ratings of Alex in the Conscious and Unconscious groups. Present the t-test findings in APA format in the Results and the R printout of the t-test in the Appendix. Also present and interpret the effect size and confidence intervals for this comparison (Confidence Intervals will be included in the R t-test output. Effect size will have to be calculated using a combination of R and hand-calculations).
• Do the same as above for Morgan.
Discussion:
• Do the findings support your predictions?
• How do our results fit with the prior literature?
• What are the broader meanings and applications of our findings? Remember, even non-significant findings may be important. How are these findings useful to you?
• What are the theoretical implications of our findings?
• What do the results suggest regarding an unconscious thought advantage in decision making, the strengths of intuitions, benefits of sleeping on things, etc?
• Suggest an original way in which we could extend research in this area.