PONE-D-24-50337 The ingroup norm of egalitarianism eliminates the association between ingroup identification and ingroup bias PLOS ONE

Dear Dr. Çoksan,

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.

Both reviewers see some merits in your manuscript but also found the current form of the manuscript needs major revisions. Both reviewers offered constructive comments from how to restructure the introduction section and the hypotheses section. Both reviewers also have suggestions for how the detailed information of the studies could be provided to assist the readers in understanding the design of the studies. Both reviewers also offer suggestions for the results section. At the current form of the manuscript, it is difficult to evaluate whether the manuscript would be further processed. However, it seems that all of the major concerns could be addressed by major revision. Thus, I invite you to submit a revised manuscript.

Please submit your revised manuscript by Mar 28 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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PLOS ONE

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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: Partly

Reviewer #2: Partly

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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: In two studies (one cross-sectional and one experimental), conducted in the intergroup context of fans of Turkish football teams, it was tested whether social norms (favouring the ingroup vs. egalitarian) moderate the association between ingroup identification and ingroup bias (operationalized as [un]equal distribution of financial resources across football clubs). It was found that ingroup identification was associated with ingroup bias only when norms favour the ingroup, while there was no association between ingroup identification and ingroup bias when norms were egalitarian.

The research question and the hypothesis were widely explored by previous research, and findings are fully in line with previous research. However, replication of well-established findings is important, and the research program includes two novelties, i.e. the intergroup context (relationships between fans of Turkish football teams) and a novel experimental manipulation of social norms.

Despite these positive remarks, in my view the article should be thoroughly revised, because the organization of the introduction and the presentation of some findings is suboptimal and not fully clear.

Introduction and theoretical justification of the research program

1. At least two issues seem crucial for the novelty of the research program, but are undertheorized. First, given that a lot of attention is paid to the importance of focusing on egalitarian norms instead of fairness norms, authors should elaborate more on the theoretical distinction between fairness and egalitarianism and, if existent, present research showing different outcomes between fairness and egalitarianism social norms, ideologies, and so on. Second, I would encourage the authors to explain more thoroughly why they think that relationships between fans of different football teams are not conflictual. News often reports clashes between rival fans, and this appears to have happened recently also in Turkey. Therefore, I do not find convincing the argument that the authors have considered a non-conflictual intergroup context. Furthermore please note that, on page 13, I would expect an explanation about the differential effects of descriptive and injunctive norms. Otherwise, the claim that injunctive norms might be more relevant to group identity than descriptive norms seems not well justified.

2. The authors have summarized literature suggesting that social norms are also formed and negotiated via social interactions in group discussions, emphasizing the active role of each group member. While I find the arguments convincing, and at the same time I have appreciated the novel and creative experimental manipulation of social norms, built on classic research, I think there is a mismatch between the theoretical rationale and the actual experimental manipulation. Indeed, there were no real group discussions, and therefore there was no negotiation. Each participants was merely invited to express their opinion after being exposed to the opinion of three other alleged ingroup members. I would encourage the authors to carefully think about the best justification for their method, and to avoid overemphasizing some strengths which might not fully apply to their method.

3. The organization of the introduction is not optimal. I would suggest to first summarize relevant literature, and then state specific hypotheses which should be based on literature. As a minor related issue, I find it surprising to first have the hypotheses about the interaction effects and then the hypotheses of the main effects. The reverse order sounds more logical. Most importantly, the section “current research” is extremely long and not very focused. For example, the first page of “current research" should be part of the theoretical summary. Most of the paragraphs are about the conceptualization of social norms (favouring the ingroup vs. egalitarian) and on the novel experimental manipulation of social norms. However, in “current research” I would expect paragraphs explaining and justifying the whole research program, and not a focus mainly on the second study. Overall, the organization of the whole introduction (from the very first page to “current research”) should be improved.

Studies 1 and 2

4. The discussion of Study 1 is partly confusing. Authors state “Moreover, high identifiers showed higher levels of ingroup bias under the favouritism norm (H1 & H2).” However, H1 and H2 are presented as hypothesis about the effects of ingroup identification for those who perceive norms as favouring the ingroup (H1) or egalitarian (H2) and not as a single hypothesis that egalitarian norms buffer the effect of ingroup identification. Then H2 is not confirmed, and the above-mentioned sentence is very imprecise.

5. The presentation of Study 2 findings is very confusing. Authors first present findings from the ANOVA, and this is fine given the 2 X 2 experimental design. It is also fine to me to decompose the interaction even if it was not significant. However, why decomposing the interaction also with social norms as predictor and ingroup identification as moderator (“Post-hoc comparisons between experimental conditions indicate that participants with favouritism ingroup norm show more ingroup bias (N = 30, M = 5.21, SE = .93) than those with egalitarianism norm condition (N = 31, M = 2.15, SE = .92; p = .021, 95% CI [.476, 5.645]) on low ingroup identification condition. Similarly, participants with favouritism ingroup norm show more ingroup bias (N = 32, M = 8.33, SE = .90) than those with egalitarianism norm condition (N = 41, M = 2.86, SE = .80; p < .001, 95% CI [3.092, 7.852]) on high ingroup identification condition.”)?

Most importantly, the following section is extremely confusing. What have the authors exactly done? Have they tested the same regression analysis of Study 1 with the measured variables (and not with the experimental manipulations)? If yes, this needs to be very well specified. The sentence “Since 2 X 2 between-subjects ANOVA results indicate the ingroup norm’s moderating role, …” is not a sufficient justification. Importantly, it makes no sense to calculate power on the explained variance of the regression analysis with measured variables. The main novelty of Study 2 is the experimental design, therefore power needs to be calculated based on ANOVA findings (or alternatively on a regression analysis with the two experimental manipulations and their interaction as predictors).

6. The discussion of Study 2 is very confusing. First, the wording “high identifiers” and “low identifiers” should not be used if authors are referring to “participants in the high identification condition” and “participants in the low identification condition”. Second, the sentence “High identifiers were more strongly influenced by ingroup norm than low identifiers under the favouritism norm condition” is very imprecise. In both identification conditions, those in the favouritism norm condition reported higher intergroup bias than those in the egalitarian norm condition, and the interaction was not significant. The authors state “It is essential to note that the ingroup norm did not have a main effect on ingroup bias in Study 1, while it produced a potent effect in Study 2, especially on those in the high identification condition. This must be the direct result of the manipulation method exclusively designed for this study”. However, their justification is in my view not correct. Indeed, in Study 2 the main effect of social norms is detected also when analysing measured social norms (and not only experimentally manipulated social norms).

7. Authors should report in the main text a justification for the sample size of both Studies. Please note that in experimental study 2 there are less than 50 participants per cell, therefore the study might be underpowered (see also the fifth comment).

Discussion

8. The discussion should be thoroughly revised after modifications are implemented to the introduction and to the presentation of Study 1 and 2 findings. Indeed, in the current version of the discussion, there are imprecisions. For example, the sentence “Moreover, the variance of ingroup bias explained by ingroup identification, ingroup norm, and their interaction is 11% in Study 1, while it is 42% in Study 2” should not be used as an illustration of the effectiveness of the social norms experimental manipulation, because it appears to refer to the regression analysis with measured variables in both studies. To make a proper comparison, authors should check the Study 2 variance explained in the ANOVA. As another example, on page 23, line 511, the authors discuss the role of “social interactions” in their social norms experimental manipulation. However, there were no social interactions, as participants expressed their opinion after being exposed to the opinion of alleged ingroup members.

Finally, I would recommend the authors to carefully re-check the article before resubmission.

I hope that these comments will be useful to the authors for their ongoing and future research.

Reviewer #2: The paper investigates the effect of group norms on ingroup bias, in particular, via comparing the induced norm of egalitarian distribution across groups to the induced norm of ingroup favoritism. In Study 1, participants themselves state the strength of their group identification, whereas in Study 2, this is manipulated in the laboratory by random assignment. The study relies on deception to generate the strength of the level of ingroup identification and different group norms.

My main comments concern hypotheses construction, the description of the design, the interpretation of the design and results of both studies.

Hypotheses:

The authors state the following: "Throughout the two studies in the current research, we hypothesized that (H1) when the

ingroup norm is favouritism, participants show more ingroup bias as ingroup identification increases, and (H2) when the ingroup norm is egalitarianism, participants show less ingroup bias as ingroup identification increases since highly identified group members are more inclined to conform to perceived ingroup norms. In terms of main effects, our expectation is

that (H3) participants with high ingroup identification show more ingroup bias than participants with low ingroup identification, and (H4) those in the condition where the ingroup norm is favouritism show more ingroup bias than those in the condition where the ingroup norm is egalitarianism."

Here, the second and the third hypothesis is at odds: If the ex-ante expectation is that high group identification leads to less ingroup bias if the group norm is egalitarian, then the main effect cannot be that ingroup bias is larger with high group identification -this will only be driven by the ingroup favoritism group norm.

Subsequent paragraphs on page 5 explain how those with low group identification would be predicted to behave. Here, the writing is unclear, as this prediction only makes sense as a comparison to those with high group identification in the current study, not stand alone. For example, what would this predict for people with low group identification: "these members still tend to look to ingroup norms to determine the correct behaviour in the social environment because these contexts provide strong guidance to members on what they should do. Thus, even individuals with low ingroup identification still follow these strong social cues to determine appropriate behaviour in the social context, indicating a tendency to conform to group norms, though to a lesser extent than high identifiers" Does this mean that those with low group identification have low ingroup bias generally or only lower than those with high group identification. If the former, is it because they are a different type of person (for example, they may be generally less "groupy" as in recent work by Kranton) or is it because, they care less about their one particular group identity.

Design:

The description of the design leaves out too many relevant details. It should be clarified how the snowball sampling was done upfront. Was it only a website, and how can there be so many recruits from a department website only? We learn much later in the paper that the participants are university students, this should be stated early on. Why call them lay people? Are there any persons who are not students? Is the first study a laboratory study -it looks like, it was not-, this is not written anywhere. How were the participants invited to the laboratory in the second study if they were participating one by one? Does this mean that there were 159 sessions? If so, how was this done, and how is this feasible?

Interpretation of Study 1 results:

The authors state the following on page 11: "however, there is no effect of ingroup identification on ingroup bias at the level where the perceived ingroup norm is more egalitarian (b = 1.37, t(184) = 1.73, p = .086)." Here, there is a moderate effect, which is not significant at the conventional level. This points to the study being underpowered. The achieved power calculation in the paper is of no guidance here either, because it is based on the overall model fit, not on the detection of an interaction effect. As such, the interpretation should reflect this, and it cannot be confidently stated that there is no effect, if anything, an egalitarian group norm deflates ingroup bias level of high group identifiers. Relatedly, Figure 1 caption states "The ingroup norm of egalitarianism eliminates the association between ingroup identification and ingroup bias." I find it misleading. egalitarianism norm weakens the association is a better description of their data.

In general, I find it very problematic to name egalitarianism "complete egalitarianism" (is there partial egalitarianism, if so, how does that look like?), and there is nothing neutral about the mid-point in their measure. One can only state that the scale from 0 to 100 measures the degree of ingroup favoritism.

Interpretation of Study 2:

On page 13, last paragraph, the authors discuss that injunctive norms may affect behavior more strongly than descriptive norms. This is likely the case, however, their design has no clear injunctive norm dimension -or if it is there, it is not explained. Moreover, their design inevitably has a descriptive norm component. These paragraphs should be clarified with respect to what the study design entails, and it should not be implied that the discussion generates an injunctive norm.

Figure 2 caption states "Intergroup comparisons point to a possible moderating role of group norm." This caption should only reflect the results, not an interpretation. So either write that group norm moderates ingroup bias, or that ingroup bias is lower with an egaliatarian norm for all group identification levels. Likewise, Figure 3 caption should just describe the result.

Other comments:

After reading the introduction, and current study sections, Study 1 comes as a surprise, because the main contribution statements relate to Study 2. So at first, I was confused that Study 1 did not have a chat.

The Discussion section, first two paragraphs should be rewritten both for clarity and for language use, e.g., "a potent effect", "hardships of applying egalitarianism". The general discussion that immediately follows is also hard to follow, either state what the hypotheses were and whether they received support in the data, or do not mention them at all. Rephrase "our much sought-after expectation". Rephrase "let us not abandon all hope."

In the same paragraph, once Turkey and once Türkiye is written.

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Reviewer #1: No

Reviewer #2: No

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PONE-D-24-50337R1 Egalitarian Norms Can Deflate Identity-Bias Link in Real-life Groups PLOS ONE

Dear Dr. Çoksan,

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.   Both reviewers have appreciated your efforts in revising the manuscript. However, both of them raised problems that they found not addressed in the revised manuscript. To avoid redundancy, please see their comments and address their points one by one.

Please submit your revised manuscript by Jul 11 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

I-Ching Lee

Academic Editor

PLOS ONE

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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: (No Response)

Reviewer #2: (No Response)

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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: Partly

Reviewer #2: Yes

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

Reviewer #1: (No Response)

Reviewer #2: Yes

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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: (No Response)

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: The authors have made considerable efforts to improve the manuscript by taking into account all the suggestions provided by the reviewers. Furthermore, as stated in my previous review, I think that this research deserves to be published – possibly in a high impact journal such as Plos One.

Besides these premises, unfortunately the current version of the article is still not fully clear, some sections and arguments are not fully convincing, and, most importantly, there is still ambiguity in the reported results.

1. Major issue:

In Study 2, the authors have deleted 2 X 2 ANOVA results, and rather just kept findings with measured identification and norms. I am aware that I made a comment about inconsistency in reporting findings which has probably been misinterpreted and which has led to this choice, and I am sorry about it. However, in my view this choice makes no sense. Study 2 is an experiment, and main data analyses need to focus on effects of experimentally manipulated variables, i.e. identification and norms. Otherwise, why conducting an experiment? I would strongly recommend that the authors report findings of the effects of experimentally manipulated norms, identification, and their interaction. Please note that the discussion includes several sentences about the effects of experimentally manipulated variables (likely kept from the previous version of the discussion) which make no sense as such findings are not reported.

Additional issues:

2. The argument that the experimental manipulation of social norms in Study 2 taps injunctive norms more than descriptive norms is not convincing. Participants read the opinion of other ingroup members (football fans supporting the same team) about how advertising revenues should be distributed, but I guess that in the real world such distribution is determined by the league and by negotiations between the league and the football clubs, with very limited voice by football fans. Therefore, the norms experimental manipulation is not much about how ingroup members (football fans supporting the same team) should act but rather about what ingroup members think. In my view this aligns more with descriptive rather than injunctive norms.

Relatedly, the authors are still referring to the experimental manipulation as “interactive” repeatedly throughout the manuscript. There was no actual interaction, because participants just read the opinion of others and expressed their opinion. While I find the experimental manipulation through a simulated discussion very thoughtful and creative, it should not be described as “interactive”.

3. The argument that the intergroup context is not conflictual is still not fully convincing. I agree that the distribution of resources task used in the outcome variable is not conflictual, but relationships between fans of different football teams can be conflictual.

4. Regarding the organization of the introduction, I think that the authors have improved it a lot compared to the previous version. However, readability could be further improved. I would recommend that the authors clearly define the following concepts, before mentioning them for the first time: differentiation, favoritism, fairness, egalitarianism. While I agree in the distinction between fairness and egalitarianism, and that egalitarianism might be a stronger means to counteract intergroup bias than fairness, the rhetoric on the distinction between the two could be clearer and more straightforward to follow.

5. The general discussion needs to be thoroughly revised after the implementation of the other changes, especially point 1.

Minor issues:

6. Study 2 sample size might not be ideal given the 2 X 2 research design. It is also still unclear which power analysis was conducted.

7. When reporting decomposition of interactions, have the authors calculated simple effects at +1 and -1 standard deviation of the moderator? This needs to be clarified in the main text.

8. I do not agree with the interpretation of the mid-point of the social norms measure. Unless there was a label associated to the mid-point, it cannot be surely known that “the midpoint does not represent a neutral position but rather an intermediate perception that ingroup members sometimes act in accordance with egalitarianism and sometimes with favouritism”. It is also possible that the mid-point is interpreted as a neutral opinion. Please note that all the lines on the mid-point might not be necessary (see next comment).

9. While Plos One might have no word limit, I think that some sections could be shortened to make the article easier to read and follow. For example, in the introduction there is one page and a half on what happens to people with low identification, but such text sounds partly repetitive. Please note that the comment on the length of the paper is determined also by the fact that this research largely replicates the theoretical rationale, hypotheses and findings by Jetten et al. (1997) and by Çoksan and Cingöz-Ulu (2022). I believe that this research program deserves to be published, the article could be shorter and, most importantly, more straightforward.

10. Finally, there might still be some inaccuracies. For example, the sentence “the relationship between ingroup identification and ingroup bias remains present even at lower levels of identification” is imprecise. The whole article should be carefully re-checked after resubmission.

Reviewer #2: I would like to thank the authors for a much improved manuscript.

I have only a few comments.

- While the authors corrected the usage of the word "neutral" when referring to mid-value of their ingroup favoritism measure, the word stays in the figures. Please change the wording in the figures as well for a correct description.

- Please include in the manuscript, maybe in the Appendix, a few example discussions generated in Study 2. Any reader is left blind as to its contents.

- Describe in text what high and low refer to in the figures; are these the extremes, or grouped values? If the latter, what are the cutoffs?

- "completely egalitarianism" should be "complete egalitarianism", and likewise, completely favouritism should be complete favouritism.

- In the first paragraph of the introduction, "In such resource allocation tasks, the perception of resource scarcity appears to promote the endorsement of zero-sum beliefs and, in turn, favouring the ingroup over outgroups [4].", I do not see how this is relevant to this work, especially in the opening paragraph. The resource allocation tasks are zero-sum, so referring to this finding generates a misleading idea of what the research is about.

- Change should to would or are expected to be in the following sentence, as you are making a prediction not a prescription for behavior: "These findings indicate that people with high ingroup identification should be more mindful of ingroup norms and accordingly revise their behaviour than people with low ingroup identification."

- "one of the few studies", not "one of the rare studies".

- Sentences with "we thought that" read unnatural and not particularly scientific. These words can be omitted.

- I do not see how the study introduces cultural dynamics, and the following claim can be made: "In this way, we thought that we could both increase the generalizability of the findings and contribute to the understanding of cultural dynamics by filling this sampling gap in the literature."

- I am not sure having different values mean in the following sentence, please specify or change wording: "Participants randomly assigned to a low ingroup identification condition, on the other hand, were informed that they have different values from their team’s other fans and were an atypical member of their ingroup."

- Please complete this phrase after "to a lesser extent" indicating the comparison unit "Our main expectation that those with higher identification in the egalitarian norm would favour their ingroup to a lesser extent was not supported in either of the studies (H2)"

- How can the authors be sure that they did not draw ultra-fans to their study? The discussion makes such a claim.

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

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Reviewer #1: No

Reviewer #2: No

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PONE-D-24-50337R2 Egalitarian Norms Can Deflate Identity-Bias Link in Real-life Groups PLOS ONE

Dear Dr. Çoksan,

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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Kind regards,

I-Ching Lee

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

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Reviewer #1: (No Response)

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Reviewer #1: Yes

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

Reviewer #1: Yes

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Reviewer #1: Yes

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Reviewer #1: Yes

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6. Review Comments to the Author

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Reviewer #1: The authors have thoroughly revised the article by taking into account the second round of comments by the reviewers. While the article is considerably improved, there are still some minor issues which need to be addressed.

1. The definition of fairness on page 3 is unclear and does not fully match what is stated later in the article about fairness.

2. Study 2 findings. The wording when reporting the decomposition is not fully clear. For example, the sentence “Post-hoc comparisons between experimental conditions indicated that participants with favoritism ingroup norm show more ingroup bias (N = 30, M = 5.21, SE = .93) than those with egalitarianism norm condition (N = 31, M = 2.15, SE = .92; p = .021, 95% CI [.476, 5.645]) on low ingroup identification condition.” Could be revised as something like “Post-hoc comparisons indicated that, among participants in the low ingroup identification condition, there was more ingroup bias among those in the favoritisms ingroup norm condition compared to those in the egalitarianism ingroup norm condition.” The following sentences should be revised as well for clarity and correctness.

3. Still on Study 2 findings. As previously explained, the main moderation hypothesis needs to be tested with ANOVA and post-hoc comparisons. However, the authors have chosen to keep results reporting the interaction tested with cross-sectional data. If the authors want to keep that section, they need to clarify the goal of such analysis, and specifically how they justify a moderation test run with measures which were initially intended to act as manipulation checks.

4. Study 2 Discussion. English language still needs to be revised. The second sentence begins with “But unlike Study 1, Study 2 revealed in this study we observed…” which is not correct. Overall, once more, the whole article should be more carefully checked.

5. Both in the Study 2 discussion and in the general discussion, the authors cannot state that their effect of experimentally manipulated ingroup norms is STRONG (or stronger), as they have not conducted a test on the strength of the effect(s). They should merely state that the effect is significant.

6. While I get the arguments by the authors, I still feel that the (long) text distinguishing between descriptive and injunctive norms has limited relevance, given that the experimental manipulation does not focus exclusively and univocally on injunctive norms. That said, I have repeated more or less the same comment three times, and it is up to the editor to decide whether this change is necessary or not.

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Reviewer #1: No

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<p>Egalitarian Norms Can Deflate Identity-Bias Link in Real-life Groups

PONE-D-24-50337R3

Dear Dr. Çoksan,

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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Kind regards,

I-Ching Lee

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: