How well animals may be able to cope with changes of habitat, specifically with rapid changes and thus novelty they encounter in an environment densely populated by humans, may be influenced by how they respond to novelty in general (Batisteli et al., 2022; Biondi et al., 2024; Castano et al., 2024; Heales et al., 2024). In considering this, it may be important to account for any difference in behavioural responses that animals exhibit when encountering a novel situation alone versus when they are doing so as part of a group.

 

Here, Allaert et al. (2025) tested how neophobia – the fear of unfamiliar objects – is affected by the social context in gulls, birds that are increasingly forced to live in urban environments due to the loss of natural coastlines. In this study, in which they reared herring gulls from egg and tested them taking into account that nestmates are not tested within the same groups, the authors found that the birds were faster to eat and spent more time in the zone of interest when they were tested in a group than when they were tested individually, specifically when a novel object was placed next to the food compared to when that object was a familiar one. The birds were also faster to enter the testing area when tested in a group, but this was not specific to the novel object condition. In addition to these changes in the average responses, the authors also report reduced variance when tested in a group in two of their three measures, namely in the latency to enter the testing area and time spent in the zone of interest.

 

The authors interpret their findings as being mostly in line with the ‘risk-dilution’ hypothesis, which is often considered in terms of predation risk (Krause & Buxton, 2002). They discuss possible reasons why other studies, with different species and different methodological setups, found support for alternative explanations.

 

The Stage 2 report was evaluated by the same two reviewers who had also reviewed the Stage 1 manuscript. In the revision, the authors focused on adding sex as a factor in their statistical models, which was the planned procedure for the statistical analyses in the Stage 1 report, and adding information regarding the problems encountered during testing and how these were handled. This specifically refers to the planned sample size (which the authors planned in the Stage 1 report taking into account both mortality and the fact that some birds would be not herring gulls but lesser black-backed gulls, which can only be established after hatching). However, there was higher than expected mortality, leading to a larger-than-planned overall reduction in sample size. During the study, the authors had contacted the recommender and discussed this issue, and the recommender advised on continuing the study and approved of the planned changes in the Stage 2 report. During the revision process, the authors added more information and also conducted an exploratory analysis, which included all birds, i.e. herring gulls and lesser black-backed gulls. This was suggested by a reviewer and the authors present this exploratory analysis in full in the supplemental material, while the main inferences are presented in the main text. In addition, during the Stage 2 review it became apparent that some minor details regarding the procedure would be useful to be included in the Stage 2 report, which the authors included in the Stage 2 revision. This did not alter the procedure as described in the Stage 1 report, but merely added more clarity to the text.

 

Based on detailed engagement with these points and the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

 
Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question was generated until after IPA.

 

 

• Peer Community Journal
• PeerJ
• Personality Science
• Royal Society Open Science

 

 

1. Allaert, R., Knoch, S., Braem, S., Debeer, D., Martel, A., Müller, W., Stienen, E., Lens, L., & Verbruggen, F. (2025). Neophobia across social contexts in juvenile Herring gulls [Stage 2]. Acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/b58ha

 

2. Batisteli, A. F., Pizo, M. A., & Sarmento, H. (2022). Female neophobia predicts the use of buildings as nesting sites in a Neotropical songbird. Animal Behaviour, 183, 151-157. https://doi.org/10.1016/j.anbehav.2021.11.008

 

3. Biondi, L. M., Medina, A., Bonetti, E. A., Paterlini, C. A., & Bó, M. S. (2024). Cognitive flexibility in a generalist raptor: a comparative analysis along an urbanization gradient. Behavioral Ecology, 35, arae025. https://doi.org/10.1093/beheco/arae025

 

4. Castano, M. V., Zumpano, F., Biondi, L. M., & García, G. O. (2024). Does urbanization affect behavioral responses to novel objects in marine birds? The Olrog’s Gull as a case of study. Urban Ecosystems, 27, 427-437. https://doi.org/10.1007/s11252-023-01465-2

 

5. Heales, H. E., Flood, N. J., Oud, M. D., Otter, K. A., & Reudink, M. W. (2024). Exploring differences in neophobia and anti-predator behaviour between urban and rural mountain chickadees. Journal of Urban Ecology, 10, juae01. https://doi.org/10.1093/jue/juae014

 

6. Krause, J. & Ruxton, G. (2002). Living in Groups. Oxford University Press, USA.

Many animals are increasingly reliant on living close or in urban environments. For them, neophobia – a trait that denotes the fearfulness of novelty (Mettke-Hoffmann, 2022) – may influence how well the species but also individuals of the same species adjust to the (human-induced) changes that characterise these environments (Lowry et al., 2013).

 

Typically, neophobia in non-human animals is assessed through behavioural tests, most often by measuring the time it takes an individual to approach a novel object or food that is positioned next to a novel object. Increasingly, resarchers are acknowledging that the social context may influence the behaviour of individuals in such situations, and several hypotheses have been proposed to explain a potential influence of social context on neophobic responses. 

 

In the current study, Allaert et al. (2024) will use a within-subject design to test three hypotheses with juvenile herring gulls (Larus argentatus): 1) the risk dilution hypothesis, accoding to which gulls will exhibit smaller neophobic responses when tested in a group than when tested alone, 2) the negotiation hypothesis, according to which gulls will exhibit stronger neophobic responses when tested in a group than when tested alone, and 3) the social conformity hypothesis, according to which those more neophobic individuals will show a smaller neohobic response when tested in a group than when tested alone while less neophobic individuals will exhibit the opposite pattern.

 

The Stage 1 manuscript was evaluated by two reviewers over two rounds of revisions. During the revisions, the authors clarified the conceptual arguments of the manuscript (including why juveniles are being tested), and edited the methods, including timing of testing, adjustments to the way that the experimental and control conditions will be run, how the planned sample size will be ensured given that at the time of testing, some chicks may be of a different species (this will become evident later on), how relatedness between the chicks will be dealt with, as well as how the behavioural coding will be conducted. Thus, the recommender judged that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/u4b7q
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA. 

 

 

 

 

1. Mettke-Hofmann, C. (2022). Neophobia. In: Vonk, J., Shackelford, T.K. (eds) Encyclopedia of Animal Cognition and Behavior. Springer, Cham. https://doi.org/10.1007/978-3-319-55065-7_908

 

2. Lowry, H., Lill, A., & Wong, B. B. (2013). Behavioural responses of wildlife to urban environments. Biological Reviews, 88, 537-549. https://doi.org/10.1111/brv.12012

 

3.  Allaert, R., Knoch, S., Braem, S., Debeer, D, Martel, A., Müller, W., Stienen E., Lens, L., & Verbruggen. F. (2024) In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/u4b7q

The Temporal Doppler Effect refers to the subjective perception that the past is further away than the future even when both temporal distances are objectively the same from the present moment (Caruso et al., 2013). In the current study, Zhang et al. ran a replication of this phenomenon and tested one possible explanation for it, namely that people overestimate the temporal distance of the past because the past is filled with more events than the future. This is because we can access information only about planned events for the future, but have access to both planned and unplanned events that happened in the past (filled-duration illusion; Thomas & Brown, 1974).

 

Over two studies, the authors found that the sampled participants reported feeling that the past was psychologically closer than the future, which is the opposite of what has previously been reported and termed the Temporal Doppler Effect (Caruso et al., 2013). In addition, the authors reported inconsistent results regarding the correlations between the psychological distance and different variables associated with the filling rate of duration. The authors discuss the differences between their own results and those by Caruso et al. (2013) in terms of methodological and contextual differences and highlight cultural aspects that may be critical to consider in future replications and overall testing of this phenomenon. As such, they highlight that, at the moment, the Temporal Doppler Effect should not be considered a robust and culturally universal phenomenon. 

 

The Stage 2 manuscript was evaluated by two reviewers who had also reviewed the stage 1 report. Following a revision by the authors, which consisted of adding the Data Availability statement, as well as a more precise summary of the results in various sections of the report, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/d9ec3/
 
Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question existed prior to Stage 1 in-principle acceptance. 

 

 

 

1. Caruso, E. M., Van Boven, L., Chin, M., & Ward, A. (2013). The temporal doppler effect: When the future feels closer than the past. Psychological Science, 24, 530-536. https://doi.org/10.1177/0956797612458804 

 

2. Thomas, E. C., & Brown, I. (1974). Time perception and the filled-duration illusion. Perception & Psychophysics, 16, 449-458. https://doi.org/10.3758/BF03198571 

 

3. Zhang, Q., Masuda, Y., Ueda, K.,Toda, K., & Yamada, Y. (2022). Is the past farther than the future? A registered replication and test of the time-expansion hypothesis based on the filling rate of duration. Stage 2 Registered Report, acceptance of Version 2 by Peer Community in Registered Reports. https://psyarxiv.com/pb47n/ 

 

Different disciplines and research areas that rely on participants’ self-reports to accrue data on participants’ true preferences are faced with the question to what extent the former can be equated with the latter. Using monetary incentivisation for study participation may influence this relationship, and researchers, especially in economics, have been discussing how to develop and implement incentive-compatible research designs, i.e., those in which the incentivisation yields the best payoff for the participant if they report their true preferences (Hertwig & Ortmann, 2011; Baillon, 2017). The Bayesian Truth Serum, first introduced by Prelec (2004), according to which participants are rewarded based on how surprisingly common their own answers are relative to the actual distribution of answers, has been proposed as a possible incentive-compatible design for survey studies that rely on participants’ self-reports about their true preferences (Schoenegger, 2021).

 

In this study, Schoenegger and Verheyen (2022) ran a replication of the study by Schoenegger (2021) and assessed whether the effect elicited by the manipulations known as the Bayesian Truth Serum is distinct from its separate constituent parts. The authors report that the manipulation did not yield a significant difference compared to control conditions, which they interpret as a failure to replicate the original results. At the same time, the authors are careful in drawing conclusions as to the usefulness of the Bayesian Truth Serum for self-report studies using Likert-scale items in general, as they emphasise that smaller effect sizes may be of interest and that the results may differ when different items are used. 

 

The Stage 2 manuscript was evaluated by two reviewers, one of whom reviewed the first Stage 1 submission, and the other one of whom reviewed the manuscript specifically to assess statistical questions.

 

Following a careful revision by the authors, the recommender judged that the manuscript meets the Stage 2 criteria and awarded a positive recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/dkvms

 

Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question existed prior to Stage 1 in-principle acceptance. 

 

 

 

1. Baillon, A. (2017). Bayesian markets to elicit private information. Proceedings of the National Academy of Science, 114(30), 7985-7962. https://doi.org/10.1073/pnas.1703486114

 

2. Hertwig, R. & Ortmann (2001). Experimental practices in economics: a methodlogical challenge for psychologists? Behavioral and Brain Sciences, 24(3), 383-403. https://doi.org/10.1037/e683322011-032

 

3. Prelec, D. (2004). A Bayesian Truth Serum for Subjective Data. Science, 306(5695), 462-466. https://doi.org/10.1126/science.1102081

 

4. Schoenegger, P. (2021). Experimental Philosophy and the Incentivisation Challenge: a Proposed Application of the Bayesian Truth Serum. Review of Philosophy and Psychology https://doi.org/10.1007/s13164-021-00571-4 

 

5. Schoenegger, P., & Verheyen, S. (2022). Taking A Closer Look At The Bayesian Truth Serum: A Registered Report. Stage 2 Registered Report, in principle acceptance of Version 3 by Peer Community in Registered Reports. https://doi.org/10.31219/osf.io/9zvqj

The Bayesian Truth Serum, first introduced by Prelec (2004) rewards participants based on how surprisingly common their own answers are in relation to the actual distribution of answers. As such, it has been suggested as a possible incentive-compatible design for survey studies in different disciplines that rely on participants’ self-reports about their true preferences (Schoenegger, 2021). 

 

In this study, Schoenegger and Verheyen propose to replicate the results reported by Schoenegger (2021) and to directly investigate whether the effect elicited by the manipulations known as the Bayesian Truth Serum is distinct from its separate constituent parts. 

 

The Stage 1 manuscript was evaluated over one round of in-depth review. Based on detailed responses to the reviewers’ comments and edits to the stage 1 report, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

 

Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.

 

 

 

 

1. Prelec, D. (2004). A Bayesian Truth Serum for Subjective Data. Science, 306(5695), 462-466. https://doi.org/10.1126/science.1102081

 

2. Schoenegger, P. (2021). Experimental Philosophy and the Incentivisation Challenge: a Proposed Application of the Bayesian Truth Serum. Review of Philosophy and Psychology https://doi.org/10.1007/s13164-021-00571-4 

 

3. Schoenegger, P., & Verheyen, S. (2022). Taking A Closer Look At The Bayesian Truth Serum: A Registered Report. Stage 1 Registered Report, in principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/dkvms 

The Temporal Doppler Effect is a phenomenon where people subjectively perceive the past to be further away than the future even when both temporal distances are objectively the same from the present moment (Caruso et al., 2013). A common explanation for this phenomenon assumes that our perception of the past and future is based on spatial and temporal analogies (Matlock, Ramscar, & Boroditsky, 2005; Casanto & Boroditsky, 2008) and that the subjective discrepancy is due to people feeling that they are moving towards the future and away from the fast, thus underestimating the temporal distance of the former and overestimating the temporal distance of the latter (Caruso et al., 2013).

 

In the current study, Zhang et al. propose to replicate the Temporal Doppler Effect as tested by Caruso et al. (2013) in study 1 and to test an alternative explanation for the effect in study 2 based on the filled-duration illusion (Thomas & Brown, 1974). This alternative explanation assumes that the subjective discrepancy is based on the difference that the past and the future are filled with events that we can remember or imagine. Because the past has already happened, it is comprised of more events (those that were planned and those that were not), while the future still exists only of events that are currently planned. 

 

The Stage 1 manuscript was evaluated over three rounds of in-depth review. The main changes during the review process involved clarifications and adaptations of the way that the authors will measure the participants’ perception of how full of events the past and the future are, as the originally proposed way measuring this did not have sufficient theoretical or empirical justifications. The authors decided to address this by firstly, clarifying this issue in the stage 1 report so that the reader is aware of the potential shortcomings of this measure, and secondly, by testing a second group of participants with an alternative measure. Based on detailed responses to the reviewers’ comments and edits to the stage 1 report, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA). 

 

URL to the preregistered Stage 1 protocol: https://osf.io/d9ec3

 

Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.

 

 

 

 

1. Caruso, E. M., Van Boven, L., Chin, M., & Ward, A. (2013). The temporal doppler effect: When the future feels closer than the past. Psychological Science, 24, 530-536. https://doi.org/10.1177/0956797612458804 

 

2. Casanto, D., & Boroditsky, L. (2008). Time in the mind: Using space to think about time. Cognition, 106, 579-593. https://doi.org/10.1016/j.cognition.2007.03.004

 

3. Matlock, T., Ramscar, M., & Boroditsky, L. (2005). One the experiential link between spatial and temporal language. Cognitive Science, 29, 655-664. https://doi.org/10.1207/s15516709cog0000_17 

 

4. Thomas, E. C., & Brown, I. (1974). Time perception and the filled-duration illusion. Perception & Psychophysics, 16, 449-458. https://doi.org/10.3758/BF03198571 

 

5. Zhang, Q., Masuda, Y., Ueda, K.,Toda, K., & Yamada, Y. (2022). Is the past farther than the future? A registered replication and test of the time-expansion hypothesis based on the filling rate of duration. Stage 1 Registered Report, in principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/d9ec3