PONE-D-21-25423Competing Social Identities and Intergroup Discrimination: Evidence from a Framed Field Experiment with High School Students in VietnamPLOS ONE

Dear Dr. Chan,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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I have selected major revision because the two reviewers have opposite recommendations. As the research question is appealing and the data analysis have been correctly performed, I think it's worthy to give you a chance as long as you address all the concerns raised by reviewer 1 about the experimental design which I share.

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Natalia Jiménez, Ph.D. Economics

Academic Editor

PLOS ONE

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Additional Editor Comments:

Dear Authors,

I have selected major revision because one of the reviewers is very satisfied with your study while the other is not. Both seem to find the reserach question and the data analysis appropriate since they do not raise any concern about them. However, I agree with reviewer 1 that you should provide more details about the design and that you must justify why you give different information in the instructions to the 2 schools you consider. In your next submission, you have to address all the points raised by reviewer 1.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: No

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The methods and procedures of the experiment have not been described in sufficient detail. Besides, the experiment might not have been conducted according to the technical standards.

It is nowhere specified how many sessions were conducted and how many participants were in each session. Were students of each class mentioned in section 4.2 conducting an independent session? Maybe a table could help to clarify this issue. Also, in page 12 lines 13-15 it is said “For Marie Curie High School students, they were also informed that the four tasks would repeat for three (BC students) or two (NC students) times, due to the experimental design.” but it is not specified the order of such repetitions and whether the order was randomized.

The main feature of the experiment that differentiates the treatments in this experiment is the matching protocol between participants. Looking at the experimental instructions provided in Appendix B, I can see that the experimental instructions provided to Minh Khai High School students for tasks 1 and 2 specify the matching protocol. However, this is not the case for Marie Curie High School students, whose instructions state, “Each of you will play this task with someone from this group.” I do not understand why at the Marie Curie sessions “all subjects were verbally informed that they would be paired with an anonymous member from the same and different language stream within Marie Curie High School, respectively.” (pag 12 section 4.5 line 4-6). In my opinion, each set of experimental instructions should have specified the particular matching a participant is involved in. This issue might be a serious problem in terms of accomplishing the technical standards of conducting experiments.

Reviewer #2: I enjoyed a lot reading the paper! I think that the authors do a fantastic job at motivating and writing it.

They conducted a framed field experiment to explore a situation where individuals have potentially competing social identities to understand how group identification and socialization affect ingroup favoritism and out-group discrimination. Despite all the evidence on this subject, this papers study teenagers which is relevant for understanding on how cooperative and competitive behaviors develop in children and adolescents, as it suggested by atuhors.

I believe that this paper could make a great publication for this journal.

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Reviewer #1: No

Reviewer #2: Yes: Diego Jorrat

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Competing Social Identities and Intergroup Discrimination: Evidence from a Framed Field Experiment with High School Students in Vietnam

PONE-D-21-25423R1

Dear Dr. Chan,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Natalia Jiménez, Ph.D. Economics

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: All my comments were addressed. Also recommendations of the other referee and the clarifications made by the authors, improve substantially the paper.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No