6 research outputs found
Generation of Laminar Vortex Rings by an Impulsive Body Force
It is shown that laminar vortex rings can be generated by impulsive body
forces having particular spatial and temporal characteristics. The method
produces vortex rings in a fluid initially at rest, and once generated, the
flow field automatically satisfies the boundary conditions and is
divergence-free. Numerical simulations and analytical models show that the
strength of these rings can be accurately predicted by considering diffusion
alone, despite the nonlinear nature of the generation process. A particularly
simple model, which approximates the source of vorticity within vertical slabs,
is proposed. This model predicts the ring circulation almost as accurately as a
model which uses the exact geometry of the source of vorticity. It is found
that when the duration of the force is less than a time scale based on the
force radius and fluid viscosity, the ring circulation can be predicted
accurately using an inviscid model.Comment: 37 pages, 11 figure
RRR: A Multi-Lab Replication of the Induced Compliance Paradigm of Cognitive Dissonance
A Large Scale Replication Project of Cognitive Dissonance Theory. Part I - Using an Induced Compliance Paradigm and a Counterattitudinal Essa
A multilab replication of the induced-compliance paradigm of cognitive dissonance
According to cognitive-dissonance theory, performing counterattitudinal behavior produces a state of dissonance that people are motivated to resolve, usually by changing their attitude to be in line with their behavior. One of the most popular experimental paradigms used to produce such attitude change is the induced-compliance paradigm. Despite its popularity, the replication crisis in social psychology and other fields, as well as methodological limitations associated with the paradigm, raise concerns about the robustness of classic studies in this literature. We therefore conducted a multilab constructive replication of the induced-compliance paradigm based on Croyle and Cooper (Experiment 1). In a total of 39 labs from 19 countries and 14 languages, participants (N = 4,898) were assigned to one of three conditions: writing a counterattitudinal essay under high choice, writing a counterattitudinal essay under low choice, or writing a neutral essay under high choice. The primary analyses failed to support the core hypothesis: No significant difference in attitude was observed after writing a counterattitudinal essay under high choice compared with low choice. However, we did observe a significant difference in attitude after writing a counterattitudinal essay compared with writing a neutral essay. Secondary analyses revealed the pattern of results to be robust to data exclusions, lab variability, and attitude assessment. Additional exploratory analyses were conducted to test predictions from cognitive-dissonance theory. Overall, the results call into question whether the induced-compliance paradigm provides robust evidence for cognitive dissonance
A Multilab Replication of the Induced-Compliance Paradigm of Cognitive Dissonance
According to cognitive-dissonance theory, performing counterattitudinal behavior produces a state of dissonance that people are motivated to resolve, usually by changing their attitude to be in line with their behavior. One of the most popular experimental paradigms used to produce such attitude change is the induced-compliance paradigm. Despite its popularity, the replication crisis in social psychology and other fields, as well as methodological limitations associated with the paradigm, raise concerns about the robustness of classic studies in this literature. We therefore conducted a multilab constructive replication of the induced-compliance paradigm based on Croyle and Cooper (Experiment 1). In a total of 39 labs from 19 countries and 14 languages, participants (N = 4,898) were assigned to one of three conditions: writing a counterattitudinal essay under high choice, writing a counterattitudinal essay under low choice, or writing a neutral essay under high choice. The primary analyses failed to support the core hypothesis: No significant difference in attitude was observed after writing a counterattitudinal essay under high choice compared with low choice. However, we did observe a significant difference in attitude after writing a counterattitudinal essay compared with writing a neutral essay. Secondary analyses revealed the pattern of results to be robust to data exclusions, lab variability, and attitude assessment. Additional exploratory analyses were conducted to test predictions from cognitive-dissonancetheory. Overall, the results call into question whether the induced-compliance paradigm provides robust evidence for cognitive dissonance