Group bias and discrimination

rich-ramsey.github.io/talks/ncm-lab-25/

Richard Ramsey
www.rich-ramsey.com

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Group bias and discrimination

Deschrijver & Ramsey, 2025, PNAS

Group bias and discrimination



Minimal groups




(Tajfel 1970, 1974)

The minimal group paradigm

  • Assign values to two other specific people (not yourself).
  • Select one option (two values).
  • Measure so-called “pull” scores.

(Tajfel 1970, 1974)

Pull scores


Three types of “pull” score are of interest.

  1. FAV vs MJP
  2. MD vs MIP/MJP
  3. FAV vs P

Each compares a discriminatory strategy against a more pro-social strategy.

Minimal group findings

(Schmidt and Drake 2023)

Minimal group tasks

Significance of the work


  • Ingroup benefit and outgroup punishment was evident, even in arbitrary or “minimal” conditions.
  • Meaningful social categories, such as race, gender, age etc., are not required to discriminate against others.

Groups and social identity theory


… explicit references to group membership are logically necessary for operationalizing in these minimal situations the major independent variable—that is, social categorization per se.


(Tajfel and Turner 1979 [p. 39])

Citation count: 41,343

Groups and social identity theory


This requires not merely that the subjects perceive themselves as similar to or different from others as individuals, but that they are members of discrete and discontinuous categories—that is, “groups”.


(Tajfel and Turner 1979 [p. 39]) [emphasis in the original]

Citation count: 41,343

Groups and social identity theory


It was as if that, just by inserting the word ‘group’ into the experimental instructions, the s’s definition of the situation was radically altered.


(Billig and Tajfel 1973 [p. 48])

Citation count: 2,538

Confound

A similarity or difference between individuals covaries with group assignment.


Conflict signals

  • Why might a similarity or difference between individuals matter?
  • Cognitive neuroscience research shows that conflict in general is an aversive stimulus that guides behaviour.
task congruent incongruent
flanker HHHHH HHSHH
Stroop RED RED

(Botvinick and Braver 2015; Dreisbach and Fischer 2015)

Conflict signals and groups

  • Could sensitivity to conflict between individuals play a role in the minimal group paradigm?

(Deschrijver and Palmer 2020)

Deschrijver & Ramsey (2025)


Research question

Are group division and social identity required to treat people differently?


Hypothesis

Resources will be allocated in favour of similar (versus dissimilar) individuals, in the absence of group division or social identity.

Comparing research designs

Original design

Deschrijver & Ramsey (2025)

Arbitrary choices/coin flip

Group division / categorisation

Money allocation / matrices

Arbitrary choices/coin flip

Group division / categorisation

✗

Money allocation / matrices

Group manipulation

No group manipulation

Comparing response wording


Group manipulation

No group manipulation

Descrijver & Ramsey (2025)

UK-based Prolific online sample. N=238 per experiment.

Raw data: minimal group dots

(Deschrijver and Ramsey 2025)

Regression parameters: minimal group

(Deschrijver and Ramsey 2025)

Individual vs group manipulation


  • Between groups design.

    • individual vs classic group manipulation

  • Coins task (random outcome).

  • N=238 per group (N=476 in total).

  • UK-based online Prolific sample.

Regression parameters: individual vs group

(Deschrijver and Ramsey 2025)

Interim summary

  • Qualitatively similar minimal group paradigm effects are obtained without group assignment.

  • But the results so far are all tied to one task.

  • We wanted to investigate the same type of question with a different task? Maybe a simpler dependent measure?

  • We setup a conflict/congruency task based on work in cognitive psychology / neuroscience.

Conflict task manipulation

self/other judgment condition
same congruent
different incongruent

Conflict task response

Congruency trial structure

Descrijver & Ramsey (2025)

UK-based Prolific online sample. N=75 per experiment.

Congruency hypothesis


Research question

Are group division and social identity required to treat people differently?


Hypothesis

More money will be allocated to others on congruent than incongruent trials, in the absence of group division or social identity.

Raw data: congruency

(Deschrijver and Ramsey 2025)

Regression parameters: congruency

(Deschrijver and Ramsey 2025)

Combined results


  • Qualitatively similar minimal group paradigm effects are obtained without group assignment.
  • Conflict tasks show that 43.1 % more money (in relative terms) is given to individuals based on arbitrary sameness versus difference outcomes, in the absence of group assignment.

Conclusion

  • Is group division required to treat people differently?

    • No

  • Sameness versus difference between individuals is important to consider theoretically and empirically.

Caution! Constraints on generality

  • We are not claiming that group division and social identity are unimportant
  • We are not claiming that differences between individuals can tell the whole story

Implications

  • Empirical: Sameness vs difference between individuals needs separating from group-based manipulations.

  • Theoretical: Social Identity Theory needs updating.

    • Other cognitive and neural mechanisms are likely to be at play, such as the affective consequences of domain-general conflict detection and resolution.

Acknowledgements

  • Inez Greven
  • Emily Butler
  • Andrew Wildman
  • Ionela Bara
  • Chris Byrne
  • Kohinoor Darda
  • Dace Apšvalka
  • Kohinoor Darda
  • Raphaël Fournier
  • Paul Downing
  • Emily Cross
  • Rudi Coetzer
  • Eliane Deschrijver
  • Rob Ward
  • Richard Binney
  • Dave Kaplan
  • Sam Parker
  • Sven Panis

And here’s my stuff


References

Billig, Michael, and Henri Tajfel. 1973. “Social Categorization and Similarity in Intergroup Behaviour.” European Journal of Social Psychology 3 (1): 27–52. https://doi.org/10.1002/ejsp.2420030103.
Botvinick, Matthew, and Todd Braver. 2015. “Motivation and Cognitive Control: From Behavior to Neural Mechanism.” Annual Review of Psychology 66 (1): 83–113. https://doi.org/10.1146/annurev-psych-010814-015044.
Deschrijver, Eliane, and Colin Palmer. 2020. “Reframing Social Cognition: Relational Versus Representational Mentalizing.” Psychological Bulletin 146 (11): 941–69. https://doi.org/10.1037/bul0000302.
Deschrijver, Eliane, and Richard Ramsey. 2025. “Unequal Resource Division Occurs in the Absence of Group Division and Identity.” Proceedings of the National Academy of Sciences 122 (7): e2413797122. https://doi.org/10.1073/pnas.2413797122.
Dreisbach, Gesine, and Rico Fischer. 2015. “Conflicts as Aversive Signals for Control Adaptation.” Current Directions in Psychological Science 24 (4): 255–60. https://doi.org/10.1177/0963721415569569.
Schmidt, Kathleen, and R. Grace Drake. 2023. “Minimal Group Procedures and Outcomes.” Edited by Norman Farb. Collabra: Psychology 9 (1): 90187. https://doi.org/10.1525/collabra.90187.
Tajfel, Henri. 1970. “Experiments in Intergroup Discrimination.” Scientific American 223 (5): 96–103. https://www.jstor.org/stable/24927662.
———. 1974. “Social Identity and Intergroup Behaviour.” Social Science Information 13 (2): 65–93. https://doi.org/10.1177/053901847401300204.
Tajfel, Henri, and John C. Turner. 1979. “An Integrative Theory of Intergroup Conflict.” In The Social Psychology of Intergroup Relations, edited by William G. Austin and Stephen Worchel, 33–47. Monterey, CA: Brooks/Cole.

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