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Determinants of Trust: Evidence from Elementary School Classrooms

J. Intell. 2025, 13(12), 165; https://doi.org/10.3390/jintelligence13120165

by Roberto Araya^*

and Pablo González-Vicente

Reviewer 1: Anonymous

Reviewer 2:

Nathan Oesch

Reviewer 3: Anonymous

J. Intell. 2025, 13(12), 165; https://doi.org/10.3390/jintelligence13120165

Submission received: 16 September 2025 / Revised: 11 December 2025 / Accepted: 12 December 2025 / Published: 15 December 2025

(This article belongs to the Special Issue Social Cognition and Emotions)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript ID: jintelligence-3904798

The manuscript presents a very interesting work in the subject of trust in a large sample (> 3000) of 4th-grade children from 135 schools in Chile. Trust was evaluated using flags as a valuable element to give to (ingroup or outgroup) or for the children to keep for themselves. In addition, the sociodemographic, economical, math’s level and personality variables were determined and its influence in trust was investigated. Results showed that intragroup trust is significatively higher than outgroup trust, and it is also higher in male than female. The authors also found that trust is associated to the four personality variables: Agreeableness, Extraversion, Openness to experience and Conscientiousness. I really believe there is both novelty and hard work in the research performed.

However, I have two important concerns about the manuscript. The first one is about the aim and scope of the journal; trust seems to me a variable far removed from intelligence. But, since the manuscript has passed the control of the journal editor, I understand that there is no problem about the journal´s aim and scope. My second concern is related to the ethical aspect. The research is performed in children from 9 to 12 years old, that is minors. The use of questionnaires such as the PPTQ-C in this kind of sample is impossible without the parents’ permission, the school´s/head permission and the authors´ university Ethical Committee´s approval. Authors state “We use open public data. We have not generated or gathered new data. Following the guidelines of the University of Chile, an ethics statement was not required for this study”. I honestly have some doubts about this. Are the personality scores of 4th-grade children public in Chile? In addition, I have serious doubts that the information obtained in the school could be published without the parents and school head´ s permission. Again, I ignore how this is regulated in Chile and, if the journal editor considers that the manuscript meets the guidelines on ethical issues, I have nothing to say about it.

Regardless of what I pointed out in the previous paragraph, the result of the manuscript review with my suggestions for improving the manuscript, is as follows:

ABSTRACT

The type of methodological design, the variables studied and the more relevant instruments to measure these variables (for example the PPTQ-C) should be included in the Abstract section.

INTRODUCTION

In the introduction section (LINES 64 67), authors state that “it needs certain economic, social, and cultural conditions for people to learn to trust unknown third parties”. However, the authors do not explain which economic, social and cultural conditions specifically influence trust and if this influence is positive or negative. I find the sentence inconclusive, and it should be elaborated and referenced.

Line 79 includes a reference dated in 2028: (Francois et. al, 2028). It should be corrected

Hypothesis 1 (Q1) includes two questions to be answered. It would be better to include the possible correlation between the trust towards the close group and the trust towards the strangers in a second hypothesis.

METHOD

The type of methodological design used should be included: a cross-sectional design. For example, in line 280, instead of writing “This is a massive study”, write “this is a cross-sectional massive study”

Describe what the vulnerability Index is.

Delete the sentence “The data was collected towards the end of the school year” because for other countries November or December are in the middle of the school year. Authors previously specified when the data was collected.

When explaining the distribution of the three socioeconomic status, high, medium and low, authors used quintiles and percentages. Instead of using both, I find that it would be better understood if the authors used percentages only.

RESULTS

Table 6 should be placed just following line 421, the line where Table 6 is cited.

Table 7 should show neuroticism values, even if it does not present significant differences.

Table 8 and line 768 the authors use the word “stickers” instead of “flags”, I understand that they are the same, if yes please change stickers to flags, and if not, please explain the difference.

DISCUSSION

Well-developed but with a relatively low number of references cited

LIMITATIONS AND FUTURE WORK

Social desirability should be included as a bias, mainly because the teacher was in the classroom when the game and questionnaire were completed.

Author Response

COMMENT 1: The manuscript presents a very interesting work in the subject of trust in a large sample (> 3000) of 4th-grade children from 135 schools in Chile. Trust was evaluated using flags as a valuable element to give to (ingroup or outgroup) or for the children to keep for themselves. In addition, the sociodemographic, economical, math’s level and personality variables were determined and its influence in trust was investigated. Results showed that intragroup trust is significatively higher than outgroup trust, and it is also higher in male than female. The authors also found that trust is associated to the four personality variables: Agreeableness, Extraversion, Openness to experience and Conscientiousness. I really believe there is both novelty and hard work in the research performed.

RESPONSE 1: Thank you very much for the time and dedication you devoted to reviewing our manuscript. We sincerely appreciate your thoughtful feedback and your recognition that the study represents a considerable amount of work with a big sample and offers a novel contribution.

COMMENT 2: However, I have two important concerns about the manuscript. The first one is about the aim and scope of the journal; trust seems to me a variable far removed from intelligence. But, since the manuscript has passed the control of the journal editor, I understand that there is no problem about the journal´s aim and scope.

My second concern is related to the ethical aspect. The research is performed in children from 9 to 12 years old, that is minors. The use of questionnaires such as the PPTQ-C in this kind of sample is impossible without the parents’ permission, the school´s/head permission and the authors´ university Ethical Committee´s approval. Authors state “We use open public data. We have not generated or gathered new data. Following the guidelines of the University of Chile, an ethics statement was not required for this study”. I honestly have some doubts about this. Are the personality scores of 4th-grade children public in Chile? In addition, I have serious doubts that the information obtained in the school could be published without the parents and school head´ s permission. Again, I ignore how this is regulated in Chile and, if the journal editor considers that the manuscript meets the guidelines on ethical issues, I have nothing to say about it.

RESPONSE 2: Thank you for your observations. We submitted the manuscript responding to the call to the topic: Social Cognition and Emotions. We believe that students’ trust is a key socio-emotional competence closely related to learning and collaboration processes. This connection explains why we believe our work fits well within this call. We also appreciate your thoughtful concern regarding ethical aspects. We fully understand its importance. The data we used is publicly available and fully anonymized, derived from educational platforms regularly used by schools. We declared this clearly to the editor and within the manuscript.

COMMENTS 3: Regardless of what I pointed out in the previous paragraph, the result of the manuscript review with my suggestions for improving the manuscript, is as follows:

ABSTRACT

The type of methodological design, the variables studied and the more relevant instruments to measure these variables (for example the PPTQ-C) should be included in the Abstract section.

RESPONSE 3: We appreciate your suggestion. We have included it in the abstract. We changed the sentence:

But the most influential factors are personality traits (measured with the Big Five model).

But the most influential factors are personality traits (measured with the Big Five model using the Pictorial Personality Traits Questionnaire for Children (PPTQ-C)).:

INTRODUCTION

COMMENTS 4: In the introduction section (LINES 64 67), authors state that “it needs certain economic, social, and cultural conditions for people to learn to trust unknown third parties”. However, the authors do not explain which economic, social and cultural conditions specifically influence trust and if this influence is positive or negative. I find the sentence inconclusive, and it should be elaborated and referenced.

RESPONSE 4: We appreciate your comment. However, we believe that the reference cited addresses this question. The abstract of (Delhey and Welzel, 2012) says: “Third, a society’s outgroup-trust extends beyond the level projected by ingroup-trust when human empowerment diminishes people’s dependence on ingroups and opens them to cooperation with outgroups. Fourth, neither cultural legacies nor social divisions absorbs the effects of empowerment and cooperation. To a large extent, trust generalizes to outgroups as a result of modernity’s emancipative impulses.” However, following your suggestion, we added another paragraph:

For example, Henrich et al. (2005) conducted behavioral experiments in 15 small-scale societies to test economic decision-making across cultures. They found that trust and fairness toward strangers varied widely, challenging the assumption of a universal “economic man.” Cooperative behavior correlated with market integration and community size—societies more engaged in markets exhibited greater trust toward anonymous others.

COMMENTS 5: Line 79 includes a reference dated in 2028: (Francois et. al, 2028). It should be corrected

RESPONSE 5: Thank you very much. It was a typo. We corrected it to 2018.

COMMENTS 6: Hypothesis 1 (Q1) includes two questions to be answered. It would be better to include the possible correlation between the trust towards the close group and the trust towards the strangers in a second hypothesis.

RESPONSE 6: We appreciate your suggestion. We separated Q1 into two questions:

Q1a: What level of trust exists towards the close group and strangers in fourth-grade students?
Q1b: What is the correlation between these two types of trust?

COMMENTS 7: METHOD

RESPONSE 7: We appreciate your comment. Our study is descriptive and cross-sectional, because it analyzes and compares data at a given point in time. Longitudinal studies, on the other hand, follow data over time. We welcome your suggestion.

COMMENTS 8: Describe what the vulnerability Index is.

RESPONSE 8: Thank you for this suggestion. We changed the paragraph to:

The socioeconomic level was calculated considering the vulnerability index of each school (VI). This is the official measure of the Chilean government for school vulnerability. It includes socioeconomic factors and the risk of school failure. The proportion of students in a situation of greater vulnerability (VI) is then calculated for each school in the country.

COMMENTS 9: Delete the sentence “The data was collected towards the end of the school year” because for other countries November or December are in the middle of the school year. Authors previously specified when the data was collected.

RESPONSE 9: Thank you for the observation. We deleted it.

COMMENTS 10: When explaining the distribution of the three socioeconomic status, high, medium and low, authors used quintiles and percentages. Instead of using both, I find that it would be better understood if the authors used percentages only.

RESPONSE 10: Thank you for this clarification. We changed

“so we divide it only into three large categories: high level, the quintile with the students with the highest scores; medium level, with 60% of cases with intermediate scores; and low level, with the quintile of students with the lowest scores.”

to:

“so we divide it only into three large categories: high level, the 20% with the students with the highest scores; medium level, with 60% of students with intermediate scores; and low level, with the 20% of students with the lowest scores.”

COMMENTS 11: RESULTS

Table 6 should be placed just following line 421, the line where Table 6 is cited.

RESPONSE 11: We agree and have changed the position of Table 6.

COMMENTS 12: Table 7 should show neuroticism values, even if it does not present significant differences.

RESPONSE 12: We also agree with the suggestion and have included them.

COMMENTS 13: Table 8 and line 768 the authors use the word “stickers” instead of “flags”, I understand that they are the same, if yes please change stickers to flags, and if not, please explain the difference.

RESPONSE 13: Thank you for this observation. We have changed to flags.

COMMENTS 14: DISCUSSION

Well-developed but with a relatively low number of references cited

RESPONSE 14: We added more references.

Harbaugh, W. T., & Krause, K. (2000). Children’s altruism in public good and dictator experiments. Economic Inquiry, 38(1), 95–109. https://doi.org/10.1093/ei/38.1.95

Seabright, P. (2004). The company of strangers: A natural history of economic life. Princeton University Press.

Sutter, M. & Kocher, M. G. (2007). Trust and trustworthiness across different age groups. Games Econ. Behav. 59, 364–382 (2007)

COMMENTS 15: LIMITATIONS AND FUTURE WORK

Social desirability should be included as a bias, mainly because the teacher was in the classroom when the game and questionnaire were completed.

RESPONSE 15: We appreciate your suggestion. We have included it.

Reviewer 2 Report

Comments and Suggestions for Authors

This is an interesting paper, that should probably be published, despite a few basic statistical issues, typos, and grammatical errors.

Suggested revisions are as follows:

Table 6, 7, and 8: In the "Effect size" column, a percentage is presented; however, this seems quite confusing and unconventional. Ordinarily, when conducting an ANOVA statistical analysis, the effect size is calculated using either Eta-Squared (η²), Partial Eta-Squared (ηₚ²), Omega-Squared (ω²), or Cohen's f²; however, based purely on what is presented in the Tables, it is not at all clear what was used for any of these analyses. Moreover, effect size is almost never presented as a percentage, but as a number between 0 and 1. For example, in the case of Cohen's f², the effect size is conventionally reported as: f²≥0.02 (small), f²≥0.15 (medium) or f²≥0.35 (large) . Please clarify the effect size test(s) used and the appropriate outcome(s) of those tests.

Additional recommendations, most of them related to grammar and diction, are included below:

Comments on the Quality of English Language

Line 101; try to avoid ending a sentence with a verb: "By the "radius of trust" we mean how wide the circle of people that the respondent himself imagines as "the majority of people" is." should be rewritten as: "By the "radius of trust" we mean how wide the circle of people that the respondent himself imagines as "the majority of people" [is in most circumstances]."

Line 289; try to avoid starting a sentence with a numerical number: "120 schools collected the data between November 18 and 24, 2022, while 16 schools did it between November 29 and December 7;" should be rewritten as: "[One hundred twenty] schools collected the data between November 18 and 24, 2022, while 16 schools [collected the data] between November 29 and December 7[.]

Line 341; missing a few key words: "The questionnaire was validated in a research with Polish students in 2014 and has the..." should be rewritten as: "The questionnaire was validated in a [previous] research [study] with Polish students in 2014 and has the..."

While care has been taken to highlight some of the more egregious grammatical and diction issues, a guarantee cannot be provided that every potential issue has been highlighted. Therefore, future manuscript submissions or re-submissions should probably be more mindful of basic grammatical and diction errors, and/or more deliberate care should be taken for Manuscripts to be thoroughly proofread by a professional native-English speaking editor or proofreader, in the interest of proper grammar, clarity, and readability, prior to submissions.

Author Response

COMMENTS 1: This is an interesting paper, that should probably be published, despite a few basic statistical issues, typos, and grammatical errors.

RESPONSE 1: We sincerely appreciate your time and dedication in reviewing our manuscript. We are very pleased with your positive evaluation across all aspects and grateful for your rigorous and constructive suggestions, particularly regarding the statistical details and grammar and diction details, which will undoubtedly help us improve the clarity of the manuscript.

COMMENTS 2: Suggested revisions are as follows:

RESPONSE 2: We had used Cohen's f². We clarified that fact. We include that: f²≥0.02 (small), f²≥0.15 (medium) or f²≥0.35 (large) Thank you very much for the suggestion.

Thus, the new paragraph is:

To determine the size of the effect of traits on trust, we used Cohen's f². We remind that f²≥0.02 and smaller than 0.15 is a small effect, f² between 0.15 and 0.35 is a medium effect, and f²≥0.35 is a large effect. Moreover, if the factor has more than two categories, we calculate the difference between the maximum and minimum value across all categories. The results are shown in Table 6.

COMMENTS 3: Additional recommendations, most of them related to grammar and diction, are included below:

Comments on the Quality of English Language

RESPONSE 3: Thank you very much for your suggestion. We made the change.

COMMENTS 4: Line 289; try to avoid starting a sentence with a numerical number: "120 schools collected the data between November 18 and 24, 2022, while 16 schools did it between November 29 and December 7;" should be rewritten as: "[One hundred twenty] schools collected the data between November 18 and 24, 2022, while 16 schools [collected the data] between November 29 and December 7[.]

RESPONSE 4: Thank you very much for your suggestion. We made the change

COMMENTS 5: Line 341; missing a few key words: "The questionnaire was validated in a research with Polish students in 2014 and has the..." should be rewritten as: "The questionnaire was validated in a [previous] research [study] with Polish students in 2014 and has the..."

RESPONSE 5: Thank you very much for your suggestion. We made the change

COMMENTS 6: While care has been taken to highlight some of the more egregious grammatical and diction issues, a guarantee cannot be provided that every potential issue has been highlighted. Therefore, future manuscript submissions or re-submissions should probably be more mindful of basic grammatical and diction errors, and/or more deliberate care should be taken for Manuscripts to be thoroughly proofread by a professional native-English speaking editor or proofreader, in the interest of proper grammar, clarity, and readability, prior to submissions.

RESPONSE 6: Thank you so much for the suggestion. We've now checked the grammar with Grammarly.

Reviewer 3 Report

Comments and Suggestions for Authors

This was a very interesting paper. I am going to list several areas where I feel this needs work.

Connecting the methods to the research questions and how these analyses will answer the research question.
The overall writing needs to be more academic (i.e. we do not refer to scholars by their entire names) and there are a lack of citations throughout.
Connecting the literature review to the purpose to the RQs and then the discussion. This was hard to see the main thesis and point throughout and deserves major attention.
It is clear translation was used but there are many phrases that are peculiar and do not actually translate well or accurately based on context of what the authors original intent was.

Comments on the Quality of English Language

I would suggest using an editor to help go through some sections that read very informally for example

It is evident that the more flags each student puts into the common well, the more
everyone will benefit, as long as everyone does it. This requires trusting others, because if
you don't trust that the other classmates will put flags in the common well, it's better not
to put any (or very few) and keep all (or almost all). A student gets the most profit when
the others donate all the flags, but he doesn't donate anything. Conversely, the worst sit-
uation is that the student donates everything and no one else does. This last possibility
awakens distrust in others. For this reason, one gives more when one trusts that others
will also donate and will not behave selfishly. This measurement instrument is known as
the "public goods game" in the literature.

This may have been translated but the translation is not actually good. The last possibility awakens distrust in others is an odd phrase.

Public good game in the literature should have several citations.

It is evident that the more flags each student puts into the common well, the more
everyone will benefit, as long as everyone does it.-- What is evident? When did you get this evidence?

Author Response

COMMENTS 1: This was a very interesting paper. I am going to list several areas where I feel this needs work.

Connecting the methods to the research questions and how these analyses will answer the research question.
The overall writing needs to be more academic (i.e. we do not refer to scholars by their entire names) and there are a lack of citations throughout.
Connecting the literature review to the purpose to the RQs and then the discussion. This was hard to see the main thesis and point throughout and deserves major attention.
It is clear translation was used but there are many phrases that are peculiar and do not actually translate well or accurately based on context of what the authors original intent was.

Comments on the Quality of English Language

I would suggest using an editor to help go through some sections that read very informally for example

This may have been translated but the translation is not actually good. The last possibility awakens distrust in others is an odd phrase.

RESPONSE 1: We sincerely thank you for your time and dedication in reviewing our manuscript and for finding it very interesting. We greatly appreciate your detailed and constructive suggestions, especially regarding the need to strengthen the connections between research questions, methods, and discussion, and to improve academic writing and translation accuracy.

We changed that sentence to:

In a public goods game where children place their flags into a common well that later doubles, gains depend on mutual trust. The more flags each student puts into the common well, the more everyone will benefit, as long as everyone does it. This requires trusting others, because if you don't trust that the other classmates will put flags in the common well, it's better not to put any (or very few) and keep all (or almost all). A student gets the most profit when the others donate all the flags, but he doesn't donate anything. Conversely, the worst situation is that the student donates everything and no one else does. This last possibility awakens distrust in others. For this reason, one gives more when one trusts that others will also donate and will not behave selfishly. This measurement instrument is known as the "public goods game" in the literature.

COMMENTS 2: Public good game in the literature should have several citations.

RESPONSE 2: Thank you for the suggestions. We added at the beginning of the discussion:

Modern economic development depends on the extraordinary human ability to trust strangers through institutions, norms, and shared expectations. This impersonal trust enables large-scale cooperation and market exchange, forming the foundation of complex economic and social systems (Seabright, 2004). Therefore, understanding how trust develops in childhood and how education can nurture it becomes a fundamental mission for both economic and democratic development. Schools are among the first institutions where children learn to cooperate beyond their families, interact with diverse peers, and build confidence in fairness and reciprocity. Other studies have investigated trust in children. For example, (Harbaugh & Krause, 2000) conducted the classic Public Goods and Dictator experiments with children aged six to twelve to investigate the development of altruism. In their version, children were divided into groups of four and given an initial endowment of tokens. In each round, they privately decided how many tokens they would contribute to a common fund (the public good) and how many they would keep for themselves (the private good). The experimenter then doubled the total contributions to the fund and divided the resulting amount equally among the four group members, independent of individual contributions. They found that children's average contributions in the Public Goods Game were generally comparable to those of adults. However, to the best of our knowledge, our study is the first in the field of trust in children with a large sample size to consider factors such as the differentiation of the ingroup from the outgroup or strangers, the type of school, and the students' personality profile.

And we added the references:

Fehr, E., Bernhard, H. & Rockenbach, B. Egalitarianism in young children. Nature 454, 1079–1083 (2008). https://doi.org/10.1038/nature07155

Harbaugh, W. T., & Krause, K. (2000). Children’s altruism in public good and dictator experiments. Economic Inquiry, 38(1), 95–109. https://doi.org/10.1093/ei/38.1.95

Henrich J, Boyd R, Bowles S, Camerer C, Fehr E, Gintis H, McElreath R, Alvard M, Barr A, Ensminger J, Henrich NS, Hill K, Gil-White F, Gurven M, Marlowe FW, Patton JQ, Tracer D. "Economic man" in cross-cultural perspective: behavioral ex-periments in 15 small-scale societies. Behav Brain Sci. 2005 Dec;28(6):795-815; discussion 815-55. doi: 10.1017/S0140525X05000142. PMID: 16372952.

Seabright, P. (2004). The company of strangers: A natural history of economic life. Princeton University Press.

Sutter, M. & Kocher, M. G. (2007). Trust and trustworthiness across different age groups. Games Econ. Behav. 59, 364–382 (2007)

COMMENTS 3: It is evident that the more flags each student puts into the common well, the more
everyone will benefit, as long as everyone does it.-- What is evident? When did you get this evidence?

RESPONSE 3: Thank you for your observation. We changed the sentence to:

In a public goods game where children place their flags into a common well that later doubles, gains depend on mutual trust.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Authors have complied with all my requests.

The manuscript is ready to be published.

Best regards

Author Response

Comments 1: Authors have complied with all my requests. The manuscript is ready to be published.

Response 1: We sincerely thank you for your time and dedication in both rounds of review. Your feedback and suggestions have substantially improved the clarity of our manuscript. We deeply appreciate your effort.

Reviewer 2 Report

Comments and Suggestions for Authors

Revisions look nearly satisfactory. Have only a few remaining comments/concerns, before recommending publication:

Table 6: As mentioned previously, the Effect size column below "Ingroup trust" and "Outgroup trust" for "AGE" should be presented as a number between 0 and 1, not as a percentage. For example, "11%" should presumably be rewritten as: "0.11", if this is, in fact, what the authors were intending to report, in their results. Please correct this issue, prior to publication.

Table 7: As mentioned previously, the Effect size column below "Outgroup trust" for "AGREEABLENESS" should be presented as a number between 0 and 1, not as a percentage. In other words, "33%" should presumably be rewritten as: "0.33", if this is, in fact, what the authors were intending to report, in their results. Please correct this issue, prior to publication.

Author Response

Comments 1: Revisions look nearly satisfactory. Have only a few remaining comments/concerns, before recommending publication:

Response 1: Thank you very much for your time in this second round. We sincerely thank you for carefully identifying the missing changes in Tables 6 and 7, as well as for your attention to detail. We apologize for not noticing these earlier and truly appreciate the constructive feedback, which helps us improve the manuscript. We have now corrected all the indicated issues.

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for the revisions.

A few things to consider in the next round of revisions.

Research question 1b assumes the answer to RQ 1a by assuming there are two types of trust. This is very clear throughout that the answer to RQ 1 was known in advance of the writing, or the writing is suggesting the answer in advance.

I would rewrite the results section to identify which analysis is answering which RQ, this section had a lot of information but it was hard to connect to the reason why.

Comments on the Quality of English Language

I provided feedback originally. I had stated there were sentences that did not make sense throughout the paper and then provided a few examples. Those sentences were corrected however, those were only examples, the entire paper is riddled with sentences similar to the ones pointed out and I believe the paper would benefit by having an editor scrutinize the language to catch some phrases and nuances.

Author Response

Comments 1: A few things to consider in the next round of revisions.

I would rewrite the results section to identify which analysis is answering which RQ, this section had a lot of information but it was hard to connect to the reason why.

Response 1: Thank you very much for your time and dedication.

We have 4 research questions:

RQ1a: What level of trust exists in the in-group and the out-group in fourth-grade students?
RQ1b: What is the correlation between these two types of trust?
RQ2: What sociobiological factors of fourth-grade students (gender, age, socioeco-nomic level, students with special teaching needs, type of school) influence levels of trust?
RQ3: Is there an influence of the personality traits of fourth-grade students on the lev-el of trust? And if there is, how does each trait influence, and to what extent?

In subsection 4.1. Relationship between intragroup and outgroup trust in children, we answered RQ1a. In order to make it clearer, we changed the first paragraph:

We ratify in this study that trust towards the close group, in this case classmates, is greater than trust towards unknown third parties (classmates from other unspecified schools). Although this is a known result in adults and was expected in children, this research helps to quantify the level of both trust and the distance between them.

to:

First, we address the research question, RQ1a: What level of trust exists in the in-group and the out-group in fourth-grade students? We confirmed a pattern previously established in adult literature: trust in the in-group is significantly greater than trust in the out-group. This specifically translates into higher trust in classmates than in unknown third parties (represented by students from other schools). While this finding aligns with existing theory and was anticipated in this age group, this research makes a key contribution by quantifying the precise level of both in-group trust and out-group trust, and, critically, measuring the quantifiable distance (difference) between these two forms of social trust among fourth-grade students. This quantification provides a crucial baseline for future studies exploring how this trust differential impacts behavioral and institutional outcomes in educational settings.

In line 619 we changed the paragraph

This difference observed between both types of trust in children and the fact that the correlation is positive and of an intermediate value (corr=0.42) supports the thesis that trust in the outgroup requires certain conditions to develop. If both trusts depended on the same factors, we would expect the distance between them to be much smaller and the correlation much higher.

Regarding RQ1b: What is the correlation between these two types of trust? We found that the observed in-group trust (trust in classmates) and out-group trust (trust in unknown students from other schools) are indeed correlated. Specifically, the correlation is positive and intermediate (r=0.42), and statistically significant. This intermediate correlation value is a key finding. It supports the thesis that impersonal, out-group trust requires certain conditions and psychological mechanisms to develop, which are partially independent of those for in-group trust. If both types of trust were simply dependent on the same general factor (e.g., general personality or parental behavior), we would expect the distance between them to be significantly smaller and the correlation to be much higher (closer to 1.0). The value of 0.42 suggests that while there is some shared psychological basis for believing others are trustworthy, the development of trust in strangers is a distinct developmental pathway.

Sections 4.2 , 4.3, and 4.4 responds to Q2: What sociobiological factors of fourth-grade students (gender, age, socioeconomic level, students with special teaching needs, type of school) influence this level of trust? Thus at the beginning of section 4.2 we added:

Sections 4.2, 4.3, and 4.4 collectively address the second research question (RQ2): What sociobiological factors of fourth-grade students (gender, age, socioeconomic level, students with special teaching needs, type of school) influence this level of trust? These three dedicated sections present our experimental results regarding how various student and school-level demographics correlate with the measured levels of both in-group and out-group trust.

Section 4.5 responds to question Q3: Is there an influence of the personality traits of fourth-grade students on the level of trust towards others? And if there is, how does each trait influence, and to what extent? Therefore at he beginning of the section we changed the first paragraph

Obviously, trust is not only affected by sociocultural factors, but also by characteristics of students, such as gender and age, which we discussed earlier. But the clearest argument in favor of the influence of personal characteristics is the relationship we find between children's personality traits and the level of trust in others. As we saw, the kinder the students, the more flags they donate to the common well; this is a fairly strong effect, greater than that of gender, age, or type of school. This result is not surprising, as there is plenty of evidence that agreeableness is a trait that promotes prosocial behaviors (OECD, 2019), among which we can consider generosity and trust in others.

To:

Now we address RQ3: Is there an influence of the personality traits of fourth-grade students on the level of trust in others? And if there is, how does each trait influence, and to what extent? We found clear evidence confirming the influence of personal characteristics. While we previously noted that trust is influenced by sociocultural factors, such as gender and age, we found that students' personality traits have a significant impact on both in-group and out-group trust. Specifically, we found that students ranking higher on the Agreeableness trait contribute more resources (flags) to the common pool. This result is not surprising, as there is substantial prior evidence that Agreeableness is a core trait that consistently promotes prosocial behaviors (OECD, 2019), which naturally include generosity and the underlying belief in the trustworthiness of others. This finding highlights the significance of personality in shaping early prosocial economic behaviors.

In addition we added the paragraphs:

Measuring trust in strangers in educational settings is critical because it offers a quantifiable window into the development of prosocial skills—a foundational pillar of any thriving society. The distinction between trust in the in-group (classmates) versus the out-group (unfamiliar students from other schools) profoundly conditions institutional outcomes.

When societies maintain a large trust gap (high in-group but low out-group trust), vital institutions like democracy, financial markets, and innovation stagnate, as cooperation is restricted to narrow circles. Conversely, when trust extends broadly to strangers, this supports impersonal rules, universal values, large-scale cooperation, civic participation, institutional effectiveness, and innovation (Henrich, 2020; Seabright, 2004). By identifying and measuring this trust differential in children, we gain the crucial knowledge necessary to design targeted educational interventions that actively foster generalized trust and enable the collective social and economic prosperity that relies on it. Our future work will continue this line of inquiry, extending the analysis to other prosocial skills, such as generosity and honesty. Our long-term aim is to help identify the precise classroom strategies and educational mechanisms that can effectively nurture and develop these essential prosocial skills.

In conclusion, this study contributes to the growing body of literature on trust by offering novel evidence from a child population, employing a rigorous behavioral methodology, and highlighting the role of personality and school context. Understanding how trust develops in early life is essential for building more cohesive and cooperative societies.

Comments 2: Comments on the Quality of English Language

Response 2: Thank you very much for your constructive feedback regarding the English language and fluency issues in the original manuscript. We sincerely appreciate your honesty and recognize that the specific examples you provided were indeed symptomatic of a widespread problem.

We have taken your critique extremely seriously and conducted a comprehensive linguistic overhaul. The entire text was meticulously re-examined using a combination of advanced AI tools (including Gemini, GPT-5, and Copilot) and then reviewed with the assistance of a professional with a deeper understanding of English.

We are confident that these extensive, sentence-level revisions have addressed all the nuances you pointed out, resulting in a manuscript that now meets a satisfactory standard for academic publication. We are grateful that your suggestion prompted this necessary and thorough improvement.

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Revisions look nearly satisfactory, according to my recommended suggestions, with respect to to the latest set of revisions, on the most recent, previously submitted Manuscript. Have only a few remaining comments/concerns, before recommending publication:

Line 44: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 46: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 79: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 134: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 139: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 180: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 182: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 344: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 346: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 395: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Lines 445-448: This sentence has been repeated, identically, word-for-word, more than three times?! Namely, the sentence: "These two indices were normalized...", has been repeated. Assume this is a major typo? Please correct this issue, prior to publication.

Line 505: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 819: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Lines 866-869: This sentence has been repeated, identically, word-for-word, at least three times?! Namely, the sentence: "If this is corrobrated in other countries...", has been repeated. Assume this is a major typo? Please correct this issue, prior to publication.

Line 966: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 1014: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 1020: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Line 1065: An illegible run-on sentence with significant overlap of characters? Please correct this issue, prior to publication.

Author Response

Comments 1: Revisions look nearly satisfactory, according to my recommended suggestions, with respect to the latest set of revisions, on the most recent, previously submitted Manuscript. Have only a few remaining comments/concerns, before recommending publication: