Going Deeper: Development and Validation of a Multidimensional DEEP Connection to Nature Scale

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Going Deeper: Development and Validation of a Multi-dimensional DEEP Connection to Nature Scale.

At the outside I was quite impressed with this manuscript as it aligned with my own comparative analysis of biophilic models.

Not only is it based around DEEP, but it also is a very deep dive into the various CTN tools that exist.

Importantly the paper argues that these tools are focussed on a unilateral connection, and these individual connections do not consider the inter-relationship of a range of factors that can concurrently impact on CTN.

However, at page 9 – on seeing the term Cronbach’s Alpha (Line 353) - I realised that I was going to be unqualified as a reviewer for this paper. Another example is Kurtosis (Line 366) – is this general knowledge amongst readers of Sustainability?

Pages 9 through to the References Section contain a significant array of statistical analysis, which makes me wonder whether the manuscript would be better placed in a Journal of Environmental Psychology, which MDPI does not seem to have.

I am concerned that the average reader would not be able to follow the statistical analyses, like me.  And therefore would not really know if what is written is correct or not – we would just have to trust the authors.

I see they have gone to an amazing amount of effort over 2.5 years in their Lab to develop this DEEP model, which is a great improvement in terms of integrating the various currently disparate models and, as they note towards the end, can be seen as a work in progress in terms of continuous improvement of such tools.

It may assist to set up a Glossary of terms so that the non-statistical reader could at least follow the gist of the statistical analysis.

Whilst this reviewer is not qualified to comment fully on this manuscript, a number of observations appear hereunder for consideration by the authors.

Just some other comments:

The references appear to be faultless regarding corresponding with the number, with the exception of line 36 noted below.

Line 32 – ‘mist’ should be ‘MIDST’

Line 36 – Leiserowitz does not appear in the References, and in any case should be cited as a number in the MDPI referencing guideline. In this case is would be number [1].

Lines 68 and 69 – should these names have references?

Line 71 – re Leopold; just for interest, the UK has just established a ‘River Rights’ law – see https://theconversation.com/rivers-are-increasingly-being-given-legal-rights-now-they-need-people-who-will-defend-these-rights-in-court-251736

Lines 93 to 208 – I am wondering if all of this text could be summarised in some sort of matrix table, with each acronym on one Axis (including the Ecospiriturality Scale), and all of the range of elements being measured on a second axis.  Maybe worth a try.

Line 275 – Maybe say what this site is  https://osf.io/5xbvp/. i.e. Connection to Nature and Pro Environmental Behaviour project tracking website

Line 293 – what is the Prolific platform?  I assume it is related to https://osf.io/5xbvp/ ?

Line 313 – re the Footnote no 2, would it not have been better to tell all the participants to see the 4 criteria for cleaning the data first i.e. if they saw this they may make a more complete attempt at the outset?

Line 323 – I really liked this table – very easy to comprehend. Below that table appear the explanation of each of the 4 DEEP elements and the scales which each one refers to. I would like to see all these sub-scales used as resources to appear in the Table/Matrix I suggest above at lines 93 to 208.

Line 523 – in Figure 1 the 20 Item DEEP CTN Scale – which is an excellent summary again – the Standardized estimates do not line up correctly with the Boxes.

Line 630 – ‘psychometric validity’. This term should be used in the Abstract to indicate the high level of statistical knowledge a reader will need to understand and replicate this study. It emerges as a critical supporting statement in lines 743 and 746 and 890 (in the Journal Psyecology) and so should be in the foreground of this analysis.

Line 671 – the authors note that these findings have significant implications in the ‘field of environmental psychology and conservation’, as noted by this reviewer earlier.

Lines 704 to 722 – I found this section very compelling, and perhaps also worth noting earlier perhaps in the Abstract.

Author Response

General Comment (1). At the outside I was quite impressed with this manuscript as it aligned with my own comparative analysis of biophilic models. Not only is it based around DEEP, but it also is a very deep dive into the various CTN tools that exist. Importantly the paper argues that these tools are focused on a unilateral connection, and these individual connections do not consider the inter-relationship of a range of factors that can concurrently impact on CTN.

Thank you very much for your kind words

General Comment (2). However, at page 9 – on seeing the term Cronbach’s Alpha (Line 353) - I realised that I was going to be unqualified as a reviewer for this paper. Another example is Kurtosis (Line 366) – is this general knowledge amongst readers of Sustainability?

Pages 9 through to the References Section contain a significant array of statistical analysis, which makes me wonder whether the manuscript would be better placed in a Journal of Environmental Psychology, which MDPI does not seem to have.

I am concerned that the average reader would not be able to follow the statistical analyses, like me. And therefore would not really know if what is written is correct or not – we would just have to trust the authors.

We believe that the term kurtosis should be known for anyone who is aware that the normality of data must be addressed. For those readers who know very little about statistics, including all the stats used to develop the scale (EFA, CFA, convergent validity, predictive validity, etc), we imagine they will need to trust that the statistics are sound, which we (and Reviewer #2) believe are.

I see they have gone to an amazing amount of effort over 2.5 years in their Lab to develop this DEEP model, which is a great improvement in terms of integrating the various currently disparate models and, as they note towards the end, can be seen as a work in progress in terms of continuous improvement of such tools.

Thank you for acknowledging that we have been extremely thorough in our creation of the scale, which took a lot of effort and time. As is typically the case in scale development, the field will continue to hone and improve the original scale.

It may assist to set up a Glossary of terms so that the non-statistical reader could at least follow the gist of the statistical analysis.

We have attempted to be more clear, but people who are aware of scale development will know our terms, and people who are not would need more than a glossary to fully appreciate the statistics. If the reviewer feels strongly that we need an appendix we are happy to oblige.

Whilst this reviewer is not qualified to comment fully on this manuscript, a number of observations appear hereunder for consideration by the authors.

 

Just some other comments:

1. The references appear to be faultless regarding corresponding with the number, with the exception of line 36 noted below. Thank you for catching this, which has now been fixed
   

2. Line 32 – ‘mist’ should be ‘MIDST’ - Thank you for catching this, which has now been fixed
   

3. Line 36 – Leiserowitz does not appear in the References, and in any case should be cited as a number in the MDPI referencing guideline. In this case is would be number [1]. Thank you for point this out, which has now been fixed
   

4. Lines 68 and 69 – should these names have references? - Thank you for catching this, which has now been fixed
   

5. Line 71 – re Leopold; just for interest, the UK has just established a ‘River Rights’ law – see https://theconversation.com/rivers-are-increasingly-being-given-legal-rights-now-they-need-people-who-will-defend-these-rights-in-court-251736 - Thank you for pointing us to this. We are aware of movements similar to this in New Zealand as well
   

6. Lines 93 to 208 – I am wondering if all of this text could be summarised in some sort of matrix table, with each acronym on one Axis (including the Ecospiriturality Scale), and all of the range of elements being measured on a second axis. Maybe worth a try.

Thank you for this great idea, we have now included a table with the details of the measures

7. Line 275 – Maybe say what this site is https://osf.io/5xbvp/. i.e. Connection to Nature and Pro Environmental Behaviour project tracking website – Thank you for pointing this out, which has now been incorporated
   

8. Line 293 – what is the Prolific platform? I assume it is related to https://osf.io/5xbvp/ ? - This is an online survey distribution website. We’ve updated this sentence to be more clear.
   

9. Line 313 – re the Footnote no 2, would it not have been better to tell all the participants to see the 4 criteria for cleaning the data first i.e. if they saw this they may make a more complete attempt at the outset?- Thank you, that is a great suggestion for our next set of studies.
   

10. Line 323 – I really liked this table – very easy to comprehend. Below that table appear the explanation of each of the 4 DEEP elements and the scales which each one refers to. I would like to see all these sub-scales used as resources to appear in the Table/Matrix I suggest above at lines 93 to 208.
    Thank you for this idea, we have added the table to include our new CTN scale
    

11. Line 523 – in Figure 1 the 20 Item DEEP CTN Scale – which is an excellent summary again – the Standardized estimates do not line up correctly with the Boxes. - This is the standard way that structural models are laid out. The standard estimates are positioned with the arrows, not the boxes.
    

12. Line 630 – ‘psychometric validity’. This term should be used in the Abstract to indicate the high level of statistical knowledge a reader will need to understand and replicate this study. It emerges as a critical supporting statement in lines 743 and 746 and 890 (in the Journal Psyecology) and so should be in the foreground of this analysis. - Thank you for that feedback. We’ve updated the abstract to include this term

 

13. Line 671 – the authors note that these findings have significant implications in the ‘field of environmental psychology and conservation’, as noted by this reviewer earlier. Our apologies, but we do not follow what is being asked of us here. Could the reviewer please clarify?

 

14. Lines 704 to 722 – I found this section very compelling, and perhaps also worth noting earlier perhaps in the Abstract. - Thank you for pointing this out. We have added some details to the abstract that highlight these results.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1. The article addresses a current and highly relevant topic — the connection to nature — situated within a context of increasing ecological urgency and the need to promote pro-environmental behaviors. The proposal of a new multidimensional scale, theoretically grounded in the integration of human beings with nature, offers an original contribution to the field of environmental psychology. The conceptualization of CTN as an integrated, non-dualistic experience between humans and nature is innovative. The creation of the acronym “DEEP” (Depth, Emotional, Experiential, Presence) provides both conceptual and communicative clarity.

2. The theoretical framework is solid, with a critical literature review that convincingly highlights the limitations of existing measures (e.g., CNS, EID, NR-6). The authors articulate well the philosophical foundations of CTN, including deep ecology and post-anthropocentric perspectives.

Suggestions for improvement:

The introduction is quite lengthy and could benefit from a more concise synthesis of core arguments to avoid redundancy.

While the philosophical influence is pertinent, some readers from applied social sciences might benefit from greater effort to operationalize these concepts.

3. The methodology is rigorous and transparent. The use of four pilot studies, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and cross-validation with pre-existing measures (CNS, EID-R, etc.) demonstrates strong psychometric care in the scale’s development. However, the low internal consistency of the “interconnected primal beliefs” subscale (α = 0.30) raises concerns and should be more explicitly addressed in the results or discussion sections.

4. The statistical analyses are well conducted and appropriate to the study's objectives. The use of a robust estimator for CFA (Satorra-Bentler) is adequate given the violation of multivariate normality.

Although the incremental explanation is relevant, the choice of control variables for incremental validity (age, political ideology, beliefs) could be more theoretically justified in the main body of the text.

5. The discussion is critical, well anchored in the results, and offers practical contributions for designing environmental interventions.

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However, the presence of a negative relationship between the emotional dimension and psychological well-being should be further explored, as it contradicts expectations and may suggest emotional dilemmas in individuals more empathetically connected to nature.

6. The article acknowledges some limitations, but could further elaborate on the potential for social desirability bias inherent in self-report measures, as well as the need for cross-cultural validation of the scale.

Author Response

General Comment (1): The article addresses a current and highly relevant topic — the connection to nature — situated within a context of increasing ecological urgency and the need to promote pro-environmental behaviors. The proposal of a new multidimensional scale, theoretically grounded in the integration of human beings with nature, offers an original contribution to the field of environmental psychology. The conceptualization of CTN as an integrated, non-dualistic experience between humans and nature is innovative. The creation of the acronym “DEEP” (Depth, Emotional, Experiential, Presence) provides both conceptual and communicative clarity.

The theoretical framework is solid, with a critical literature review that convincingly highlights the limitations of existing measures (e.g., CNS, EID, NR-6). The authors articulate well the philosophical foundations of CTN, including deep ecology and post-anthropocentric perspectives.

The statistical analyses are well conducted and appropriate to the study's objectives. The use of a robust estimator for CFA (Satorra-Bentler) is adequate given the violation of multivariate normality.

Thank you for your kind words

Suggestions for improvement:

1. The introduction is quite lengthy and could benefit from a more concise synthesis of core arguments to avoid redundancy. - We agree with the reviewer and we have now made changes to be more concise and shorten both the intro and the discussion

 

 

2. While the philosophical influence is pertinent, some readers from applied social sciences might benefit from greater effort to operationalize these concepts. - We have made more clear our discussion of their philosophical influences which we believe has helped to operationalize these concepts.
   

3. The methodology is rigorous and transparent. The use of four pilot studies, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and cross-validation with pre-existing measures (CNS, EID-R, etc.) demonstrates strong psychometric care in the scale’s development. However, the low internal consistency of the “interconnected primal beliefs” subscale (α = 0.30) raises concerns and should be more explicitly addressed in the results or discussion sections. - We’ve updated the footnote we previously had on this issues (number 3)to acknowledge that the primal beliefs scale is new and may show variability across samples as more data is collected. Because primal beliefs was not a germane to the study we prefer to not explore this in detail in the discussion.

4. Although the incremental explanation is relevant, the choice of control variables for incremental validity (age, political ideology, beliefs) could be more theoretically justified in the main body of the text. - Under demographics we say: “Previous reviews on individual difference predictors of PEB have found mixed evidence for age, gender, political ideology, and socio-economic status (SES) on PEB [30,43,57]. As such, these items were included in the study to account for possible covariation in PEB”
   Because we’ve asked to shorten the paper, we prefer not to elaborate further than this. If the reader would like to read about these covariates, we have provided the relevant citations.
   

5. The discussion is critical, well anchored in the results, and offers practical contributions for designing environmental interventions. However, the presence of a negative relationship between the emotional dimension and psychological well-being should be further explored, as it contradicts expectations and may suggest emotional dilemmas in individuals more empathetically connected to nature. - Thank you for this feedback. We have now made this section more clear. The inclusion of well-being was exploratory and we feel that further posturing about the unexpected results should wait until replication.
   

6. The article acknowledges some limitations, but could further elaborate on the potential for social desirability bias inherent in self-report measures, as well as the need for cross-cultural validation of the scale.
   - Regarding cross-cultural validation, the original and revised version addressed this in the limitations: “Third, our samples were predominantly from WEIRD (Western, educated, industrialized, rich, democratic) populations. This limits cross-cultural validity and may fail to capture experiences driven by cultural differences. Validating the DEEP CTN Scale with more diverse populations globally is an important next step, as, while we attempted to make the language in the items inclusive to many nature-based experiences, it is unclear that we have succeeded in this aspect.”
   - Regarding social desirability, we agree that this phenomenon likely biases the vast majority of people asking about positive attitudes and behaviors. However, the real issue is whether one thinks that this phenomenon is creating spurious findings. In our case, the fact that only some of our dimensions of CTN predicted our outcome measures suggests