Why Social Psychology Matters

1A radio drama as an experiment

Since 2004 the Dutch non-governmental organisation La Benevolencija has broadcast Musekeweya ("New Dawn"), a radio drama about two neighbouring villages that move from conflict towards reconciliation. Its storylines were written using social psychology: how ordinary people are drawn into violence, and how individuals can resist and help.

The psychologist Elizabeth Levy Paluck (2009) tested it with a year-long field experiment. Listening groups in Rwandan communities were randomly assigned to hear either Musekeweya or a different radio drama about health. At the end of the year, the reconciliation drama had changed listeners' perceptions of social norms (what they believed their community considered acceptable, such as trusting others, marrying across groups and speaking openly about painful issues) and some of their behaviours, such as willingness to express disagreement and to cooperate. It did little to change their personal beliefs.

The study shows two things at once: social psychology can be put to work on a society's most serious problems, and it can measure honestly whether its ideas work.

21. Where social psychology is used

32. Why the discipline had to look at itself

Social psychology is only useful if its findings are true. From about 2011 the field faced a replication crisis. The Open Science Collaboration (2015) repeated 100 studies published in 2008 in three leading psychology journals. While 97% of the original studies had reported statistically significant results, only 36% of the replications did, and the average effect was about half the original size. Social psychology fared worse than cognitive psychology.

Two famous findings that did not survive

• The Stanford Prison Experiment (Philip Zimbardo, 1971). Twenty-four male students were randomly made "guards" or "prisoners" in a mock prison; the study was stopped after six days because some guards became abusive. It was long taught as proof that roles alone turn ordinary people cruel. Archive recordings later showed that the guards had been briefed and encouraged to be tough, and that some participants were acting (Thibault Le Texier, 2019). Only some guards behaved cruelly, and the BBC Prison Study (Haslam and Reicher, 2002), which did not coach its guards, found that they did not slip naturally into tyranny. The study is now best taught as a lesson in research design and ethics, not as evidence about human nature.
• Ego depletion. Roy Baumeister and colleagues (1998) proposed that self-control draws on a limited store of willpower that is "used up" by one task, so people do worse on the next. Hundreds of studies seemed to agree. But a registered replication across 23 laboratories with over 2,000 participants (Hagger and colleagues, 2016) found an effect close to zero, and a second multi-lab test in 2021 also found at most a tiny effect.

How the field responded

Psychologists now increasingly pre-register their hypotheses and analyses before collecting data, run large multi-laboratory replications, share their data, and publish studies whose results turned out null. They have also recognised that most participants came from "WEIRD" societies (Western, Educated, Industrialised, Rich and Democratic): Joseph Henrich and colleagues (2010) noted that 96% of participants in top psychology journals came from countries with about 12% of the world's population. Studies run in Africa, such as Paluck's in Rwanda, help correct this bias.