#81706 | AsPredicted

'The effect of rumination on conspiracy beliefs'
(AsPredicted #81706)

Created:       12/02/2021 05:06 AM (PT)

This is an anonymized version of the pre-registration.  It was created by the author(s) to use during peer-review.
A non-anonymized version (containing author names) should be made available by the authors when the work it supports is made public.

1) Have any data been collected for this study already?
No, no data have been collected for this study yet.

2) What's the main question being asked or hypothesis being tested in this study?
This study tests whether rumination about a fictional scenario increases conspiracy beliefs about this scenario. We expect that the experimental group that ruminated about the scenario will report greater conspiracy beliefs than the control group that did not ruminate.

3) Describe the key dependent variable(s) specifying how they will be measured.
The dependent variable consists of six items measuring a) specific conspiracy beliefs about each scenario (three items, e.g. "The plane crash is part of a secret plan to take out the political opposition" (Scenario A), or "Social media firms are secretly activating smartphone microphones to monitor the whole population" (Scenario B)) and b) more general conspiracy beliefs than can be applied to both scenarios (three items, e.g. "There are many important things about this that the public will never know about"). We will test in an exploratory factor analysis whether these items load on a single factor, and build scales according to these results.

4) How many and which conditions will participants be assigned to?
Participants will be randomly assigned to one of four conditions: Scenario A + rumination, scenario A control, scenario B + rumination, scenario B control. Scenario A is a fictional newspaper report about a politician dying in a plane crash (adapted from Leman & Cinnirella, 2013). Scenario B is a fictional newspaper report about social media platforms being under suspicion to listen to user's conversations through smartphones.
Rumination will be induced by asking participants to think about several questions in a stepwise procedure. First, participants are asked to write down what spontaneously comes to mind to the following question: "Why did this happen?". Then, they are asked to think about this question again more thoroughly, and write down everything that comes to mind (at least three sentences, more is appreciated). The same procedure is repeated for the question "Which concerns does this cause you?". Lastly, participants are asked to think about these questions again jointly, and to write down their thoughts in one paragraph.
The control group will proceed to the dependent variables right after reading the scenario.

5) Specify exactly which analyses you will conduct to examine the main question/hypothesis.
We will check assumptions of normality and homogeneity of variance. If not violated, we will conduct student's t-tests to compare means in conspiracy beliefs between rumination and control conditions for each scenario separately. If assumptions are violated, we will conduct non-parametric tests of mean differences.

6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations.
Participants below the age of 18, and participants who failed the following attention check will be excluded automatically and not proceed to the end of the survey: Scenario A: "You read a text about a person dying in a plane crash. What was that person's profession?"; Scenario B: "You read a text about certain firms. What kind of firms was it about?"
We will also exclude participants who spent less than 20 seconds on any of the three pages of the rumination manipulation, and participants who indicated at the end that they did not participate seriously. We will also check the open text fields of the rumination manipulation, and exclude participants who wrote down unrelated content or nonsense.

7) How many observations will be collected or what will determine sample size?
No need to justify decision, but be precise about exactly how the number will be determined.

In order to detect a medium-sized mean difference (d = .50) with a power of .90 and alpha = .05, 86 participants per group are needed. We will aim for a sample size of n = 100 per group to allow for potential exclusions (N = 400).

8) Anything else you would like to pre-register?
(e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?)

We will also include baseline measures of conspiracy mentality (Bruder et al., 2013) (before the experimental manipulation). We examine whether participant's baseline conspiracy mentality moderates the effect of rumination on conspiracy beliefs, and whether the manipulation also affects endorsement of more plausible statements about the scenario (three items per scenario, e.g. "This was an accident caused by human failure" (Scenario A), "These advertisements where shown because they fit well to other items the user looked for on the internet" (Scenario B)).