Experimental study on the role of social norms in political discrimination

Last registered on December 11, 2022


Trial Information

General Information

Experimental study on the role of social norms in political discrimination
Initial registration date
October 13, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
October 17, 2022, 5:31 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
December 11, 2022, 5:40 PM EST

Last updated is the most recent time when changes to the trial's registration were published.


Primary Investigator

Institute of Public Goods and Policies, Spanish National Research Council

Other Primary Investigator(s)

PI Affiliation
University of Nottingham Ningbo China
PI Affiliation
Spanish National Research Council

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Previous studies have documented the primacy of partisan affective polarisation over other social cleavages (i.e. race, religion or ethnic identities) in western democracies. Partisan affective polarisation is understood as a form of hostility and prejudice that operates across political lines. It involves interpersonal evaluations and behaviours towards other individuals based on their political affiliation, and may result in social, political and economic discrimination. The question is why are people more polarised by partisanship than their regional, linguistic, ethnic or religious affiliations? An increasingly common answer is that interactions across race, religion, gender and other social divides are constrained by social norms, but there are no corresponding pressures or sanctions that prevent discrimination and hostility towards political opponents.
Here, we present a research design to test this “lack-of-social-norms” hypothesis on political discrimination. The design involves laboratory experiments investigating the relationship between discriminatory behaviour and the perceived social inappropriateness of discrimination. Our hypothesis is that participants will perceive it to be more socially inappropriate to discriminate on the basis of nationality or gender than on the basis of political identities.
External Link(s)

Registration Citation

Lane, Tom, Luis Miller and Isabel Rodríguez Marín. 2022. "Experimental study on the role of social norms in political discrimination." AEA RCT Registry. December 11. https://doi.org/10.1257/rct.10172-1.1
Experimental Details


We will recruit participants based on relevant characteristics and invite them to the experimental sessions. In the laboratory, we will bring up one of these characteristics in order to elicit one dimension of their identity. After this priming, participants will carry out two incentivised tasks: an allocation game and a norm-elicitation task.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Economic discrimination, evaluations of social appropriateness.
Primary Outcomes (explanation)
Economic discrimination (results from the allocation task); evaluations of social appropriateness (results from the norm-elicitation task).

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The dimension of identity that is primed in every experimental session is varied exogenously, constituting our main treatment.
Experimental Design Details
In the laboratory, we will prime participants to think about particular dimensions of their identities. We will do so by physically separating them in four different groups in the lab, and reminding them via a computer message that they are part of a particular group (based on partisanship, religious affilition or random assignment). This priming aims to trigger a process of social identification by encouraging subjects to identify with some participants in their experimental session and not with others. The dimension of identity that is primed is varied exogenously between partisanship (identity where we hypothesise weak norms against discrimination), religious affiliation (identity where we hypothesise strong norms against discrimination) and randomly-selected teams (control group). This variation constitutes our main treatment. After priming one side of their identities, participants will carry out the two tasks that conform the core of the experiment. The order in which the tasks are presented to them will be randomised to control for behavioural effects from eliciting norms.
Participants will be invited to participate and assigned to one of the identity groups based on results from a pre-survey. In the case of the artificial or randomly-selected treatment, individuals will blindly draw a ball from a bag. The colour of said ball determines which group they will be assigned to. Each experimental session will have a similar distribution of participants in terms of ideology and religious affiliations, but only one of these identities (or none) will be brought up during the session.
Randomization Method
Randomization done in office by a computer
Randomization Unit
Experimental sessions
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
12 experimental sessions
Sample size: planned number of observations
Between 250 and 300 participants
Sample size (or number of clusters) by treatment arms
4 experimental sessions (aprox. 90/100 participants) by treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Nottingham School of Economics Research Ethics Committee
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information


Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials