Part of the Learn library.
Psychology has changed a great deal since the early 2010s. Large, coordinated attempts to repeat well-known experiments found that many published effects were smaller than first reported, and some did not appear at all. In the best-known project, 270 researchers repeated 100 studies from three leading journals; 97 of the originals had reported a significant result, and only 36 of the repeats did, with effects on average about half the original size [1]. Later projects that repeated the same study in dozens of labs at once found a similar picture: some classic effects held up cleanly, others vanished [2][3].
That history matters for an archive about persuasion, because some of the most quoted findings about how people can be influenced are among the ones that did not hold up. So every page in this library carries a rating, and a section called "Has it held up?" that says why.
The ratings
- Strong. Replicated many times, by independent teams, often in large multi-lab or pre-registered studies, and supported by meta-analyses (studies that pool many studies). The size of the effect may still vary by setting, and the page says so.
- Moderate. Well supported, but with open questions about how large the effect is, how far it generalises beyond the lab or beyond Western student samples, or how it works.
- Mixed. Some findings in the area are solid and others are not, or meta-analyses disagree. The page separates the two.
- Contested. A famous claim that has failed important replications, or whose standard account has been seriously challenged by later work. The page still explains it, because it is widely cited and sometimes used, but it tells you what the challenge is.
A rating describes the research on the psychological mechanism. It is not a judgement about any political example on the page, and it is not a score of any person, party or cause.
How the pages treat politics
The same definitions apply to every side, party, country and era. Each page draws examples from across the political spectrum and from governments and movements a reader may sympathise with, including the reader's own country and its allies. Where the research itself finds differences between groups (for example, left and right), the page reports what the studies found and how strong that evidence is, including when later studies disagreed.
Sources
- Open Science Collaboration. (2015). Estimating the reproducibility of psychological science. Science, 349(6251), aac4716. https://doi.org/10.1126/science.aac4716
- Klein, R. A., et al. (2014). Investigating variation in replicability: A "Many Labs" replication project. Social Psychology, 45(3), 142–152. https://doi.org/10.1027/1864-9335/a000178
- Camerer, C. F., et al. (2018). Evaluating the replicability of social science experiments in Nature and Science between 2010 and 2015. Nature Human Behaviour, 2(9), 637–644. https://doi.org/10.1038/s41562-018-0399-z