Follow-Up Experiment: Masculinity Norms in Brazil Among Adolescents

Last registered on April 09, 2024


Trial Information

General Information

Follow-Up Experiment: Masculinity Norms in Brazil Among Adolescents
Initial registration date
April 03, 2024

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
April 09, 2024, 5:07 PM EDT

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



Primary Investigator


Other Primary Investigator(s)

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Social norms are sometimes misperceived, which has consequences for important economic outcomes. However, little is known about why misperceptions exist in the first place. This project focuses on the role of communication in shaping misperceptions, which I study in the context of masculinity norms among 8th to 9th graders in urban Brazil, in collaboration with the Secretariat of Education of the
City of Rio. In this study, I ask adolescents to self-select into groups to learn peers’ opinions about masculinity, specifically about two traditional beliefs: men who cry are weak, and men should use violence to get respect if necessary. To estimate treatment effects, I randomly allocate participants to answer the outcome variables either before or after the discussion.
External Link(s)

Registration Citation

Matavelli, Ieda. 2024. "Follow-Up Experiment: Masculinity Norms in Brazil Among Adolescents." AEA RCT Registry. April 09.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
- Misperceptions with respect to two beliefs about masculinity: Men Who Cry Are Weak, and Men Should Use Violence to Get Respect if Necessary
- First-order beliefs about Men Who Cry Are Weak and Men Should Use Violence to Get Respect if Necessary
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
- Self-reports on whether want to be an emotional support peer at the school and on whether want to be a person to report cases of bullying to the school board
- Before and after comparisons (not randomized): how interested were in listening their peers' opinions in the discussions (on a scale from 1 - not interested at all to 10 - very interested); how comfortable think would feel/felt in the discussion (on a scale from 1 - not comfortable at all to 10 - very comfortable); and how connected would feel with their peers (on a scale from )
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
In each classroom, all participants self-select in groups of about 5 to 6 people -- although there might be some other natural variation in the number of peers in a group. I then ask then to read the instructions in the survey, which asks them to discuss their peers' opinions about masculinity, specifically about the statements that Men Who Cry are Weak and Men Should Use Violence to Get Respect if Necessary. There is no right or wrong: they should listen and respect their peers' opinions. The discussions were partially mediated: three people of the research team would rotate across the groups, asking if they had talked and trying to make sure everyone heard each other's opinions.

The randomization consists of the following: stratified by sex, some people are randomly asked about the Primary and Secondary outcomes before the discussion, and others are asked afterward. The survey platform automatically performs treatment assignments.

Everyone is asked about the before-and-after outcomes on interest in the discussion, predicted level of comfort, and connection with the peers.

Note: I will also show results in the Appendix of a pilot school in which mediation was not used in the discussions.
Experimental Design Details
Randomization Method
randomization done in office by a computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
3-5 schools
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Rough sample size:
125-250 control students (presented with outcomes of interest before the discussion)
125-250 treated students (presented with outcomes of interest before the discussion)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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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