Music is a universal across human cultures, but there is debate as to why and how it evolved. For example, Pinker has famously argued that music is “auditory cheesecake,” with no biological value (Pinker, 1997). Most scholars on the evolution of music make comparisons with language, another human universal that is unique to our species (Friederici, 2017). A current leading hypothesis in the evolution of music is the social bonding hypothesis, which suggests that music plays a special role in social bonding beyond the role that language plays (Savage et al., 2021).

 

Previous studies have provided evidence that synchronized music-making can promote social bonding (e.g. Stupacher et al., 2021). However, it is unclear whether synchronous singing provides any advantage in social bonding as compared to merely speaking. Previous work on this topic has at times lacked sufficient controls and has potentially been subject to publication bias—it could be that only the studies with statistically significant findings are in the published literature, when in fact additional experiments may have been run with unpublished null results. Also critically, prior studies have been subject to sampling bias—the vast majority are limited to a small set of cultures and musical styles, focusing primarily on English-speaking cultures and western music (Henrich & Heine, 2010). If music has evolved as a mechanism for social bonding, then it is especially critical to demonstrate its effects on social bonding across a wide range of cultures.

 

In a remarkable global collaboration including 88 collaborators from six continents, Savage et al. (2025) plan to collect data on synchronized singing and speech from 1710 participants across 57 research sites. Participants will be assigned to participate in (1) a synchronized singing activity, (2) a synchronized speech activity, or (3) a natural, prompted conversation.

 

At each research site, participants will gather in groups of 5-10 and will be randomly assigned to one of the three conditions (for the research site to be valid, it must recruit one group of participants into each condition). The experiment will start with pre-test measures of social bonding and other variables. Next, the intervention will commence. In the singing condition, participants will synchronously sing a song that is highly familiar in that culture. In the lyrics recitation condition, participants will synchronously speak printed lyrics to the songs from the singing condition (twice through, to account for speed differences in song and speech). In the conversation condition, participants will have a natural conversation in response to an ice-breaker question. Finally, each group will engage in post-test measures of social bonding as well as debriefing.

 

The social bonding hypothesis predicts that participants in the synchronized singing task will experience more social bonding (as measured by a pre- and post-test differences) than will participants who engage in sequential conversation or synchronous lyrics recitation in the absence of musical pitch or rhythm. The unprecedented scale of this global, cross-cultural investigation will make a great impact on the field and on our understanding of the relationship among speech, song, and social connection, regardless of the outcome.

 

Four expert reviewers provided valuable feedback through two rounds of review. Based on ​detailed responses to the reviewers’ and the recommender’s comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance.​​​

 

 

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.
 
List of eligible PCI RR-friendly journals:

 

• Advances in Cognitive Psychology
• Biolinguistics
• Collabra: Psychology
• Experimental Psychology *pending editorial consideration of disciplinary fit
• International Review of Social Psychology
• Journal of Cognition
• Peer Community Journal
• PeerJ
• Royal Society Open Science
• Social Psychological Bulletin
• Studia Psychologica
• Swiss Psychology Open
  
  

 

1. Friederici, A. (2017). Language in Our Brain: The Origins of a Uniquely Human Capacity. https://doi.org/10.7551/mitpress/9780262036924.001.0001

 

2. Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? Behavioral and Brain Sciences, 33, 61-83. https://doi.org/10.1017/s0140525x0999152x

 

3. Pinker, S. (1997). How the mind works. WW Norton & Company.

 

4. Savage, P. E., Loui, P., Tarr, B., Schachner, A., Glowacki, L., Mithen, S., & Fitch, W. T. (2021). Music as a coevolved system for social bonding. Behavioral and Brain Sciences, 44, e59. https://doi.org/10.1017/S0140525X20000333

 

5. Savage, P. E. et al. (2025). Does synchronised singing enhance social bonding more than speaking does? A global experimental Stage 1 Registered Report. In principle acceptance of Version 7 by Peer Community in Registered Reports. https://osf.io/7t4ck

 

6. Stupacher, J., Mikkelsen, J., & Vuust, P. (2022). Higher empathy is associated with stronger social bonding when moving together with music. Psychology of Music, 50, 1511-1526. https://doi.org/10.1177/03057356211050681

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 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/ 

 

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.

Social cognition involves complex processes including empathy, mentalizing, and compassion, which rely on structural connectivity and specifically white matter (WM) integrity. Prior research suggests that deficits in social cognition are linked to deficient structural connectivity, indicating that the latter might be an essential foundation for social cognitive abilities. In the current study, Hansl et al. (2025) explore the relationship between social cognition and white matter (WM) integrity in the brain across different populations, by means of a systematic review and meta-analyses. Using diffusion-weighted imaging data, the authors aim to identify specific WM tracts most associated with social cognition. Meta-analyses of region-of-interest (ROI)-based studies will provide further insights, while meta-regression and subgroup analyses will examine differences across social cognitive constructs, imaging metrics, clinical conditions, and age groups. The findings could clarify global and specific WM contributions to social cognition, guiding future research on brain structure-function relationships in social cognition across various populations.

 

The Stage 1 submission was evaluated by two expert reviewers. After two rounds of revision, 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/6n3jy (under temporary private embargo)

 

Level of bias control achieved: Level 2. At least some data/evidence that will be used to answer the research question has been accessed and partially observed by the authors, but the authors certify that they have not yet observed the key variables within the data that will be used to answer the research question and they have taken additional steps to maximise bias control and rigour.

 
List of eligible PCI RR-friendly journals:
 

 

 

1. Hansl, R., Maliske, L. Z., Valk, S. L., & Kanske, P. (2025). Social cognition as a matter of structural brain connections? A systematic review and diffusion weighted imaging meta-analysis. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/6n3jy