on certain topics.<sup>33</sup> The survey was conducted with all adolescents living in sampled households who fell into the targeted age range. In total, information from 3,237 adolescents across 2,393 households was collected at baseline.

# **5.2 Lab-in-the-Field Experimental Data**

Lab-in-the-field experiments supplement the survey data at endline. The experiments allow us to study in which way gender attitudes differ if expressed privately or publicly. To do this, we first randomly grouped participants into teams of five with different gender compositions and asked them to choose a leader and deputy for the team. Next, each adolescent in the experiment sample was privately interviewed and asked to choose if they agree or disagree with three gender attitudes statements and play two line-match games in private. During the line-match game, participants were shown a set of lines and they were asked to indicate which of these lines had the same length as the reference line which was also shown to them. Next, we repeated the two exercises in their team setting. That is, all participants were asked to express their gender attitudes and the line choice in their teams one after the other in public where they could deviate from their private answers. We use the private and public statements to measure social conformity which is similar to the conformity line game conducted by the psychologist Solomon Asch (Asch, 1951, 1952). Further details of the lab-in-the-field experiments are included in the Appendix.

The aim was for each community cluster in the study sample to host at least two experimental sessions. Each of these sessions consisted of 20 adolescents (10 girls and 10 boys) divided into four teams, each with one of four gender compositions (all boys, all girls, mixed majority boys, mixed majority girls). Each team included both control group and treatment group participants. Games were completed for a subset of the study sample randomly selected.<sup>34</sup> The lab-in-the-field experimental games were completed between November 2020 and June 2021 to coincide with the endline.

# **5.3 Balance Check and Sample Description**

In Table 1 we show that the randomization produced balanced groups at baseline on a set of observable covariates. The sample is distributed across different types of communities with approximately 40% internally displaced persons (IDP), 40% urban, and 20% rural. The

> 33The midline survey also included questions on participation in the _Choices_ training, additional beliefs and community norms, time use, household chores, and a module to capture social desirability bias. We capture social desirability bias through the 13-item social desirability scale, which Reynolds (1982) demonstrates is a viable substitute for the 33-item Marlowe-Crowne scale. The endline survey included additional questions on marital status, fertility, and girls’ menstruation status in the adolescent questionnaire as these questions may have become applicable to some of the older adolescents in the study. For both adolescents and adults, we included a measure of generalized self-efficacy (Schwarzer and Jerusalem, 1995). Parents’ expectations on fertility, marriage, and FGM for adolescents was also collected.

> 34The sampling for the lab-in-the-field experiment was stratified by community cluster, gender of the adolescent and treatment status. Replacement names were also shared with the implementing partner who were instructed to ensure each session had exactly 20 adolescents with an equal representation of male and female adolescents plus treatment and control adolescents.

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