If you would like a copy of any of the publications listed below, please email



Baumgartner, H.A., Alessandroni, N., Byers-Heinlein, K., Frank, M.C., Hamlin, J.K., Soderstrom, M., … & Coles, N.A. (2023). How to build up big team science: A practical guide for large-scale collaborations. Royal Society Open Science, 10(6).

Drew, R., Tan, E., Yuen, F., & Hamlin, J.K. (2023). We aren’t especially fearful apes, and fearful apes aren’t especially prosocial. Behavioural and Brain Sciences, 46, 60. doi:10.1017/S0140525X22001807

Proulx, J., Van de Vondervoort, J. W., Hamlin, J. K., Helliwell, J. F., Aknin, L. (2023). Are real-world prosociality programs associated with greater psychological well-being in primary school-aged children? International Journal of Environmental Research and Public Health, 20(5): 4403.

Woo, B., Tan, E., Yuen, F., & Hamlin, J.K. (2023). Socially evaluative contexts facilitate mentalizing. Trends in Cognitive Sciences, 27(1), 17-29.


Kominsky, J. F., Lucca, K., Thomas, A. J., Frank, M. C., & Hamlin, J.K. (2022). Simplicity and validity in infant research. Cognitive Development, 63.

Woo, B., Tan, E., & Hamlin, J.K. (2022). Human morality is based on an early emerging moral core. Annual Review of Developmental Psychology, 4, 41-61.

Margoni, F., Block, K., Hamlin, J.K., Zmyj, N., & Schmader, T. (2022). Meta-analytic evidence against sex differences in infants’ preference for prosocial agents. Developmental Science.

Visser, I., Bergmann, C., Byers-Heinlein, K., Dal Ben, R., Duch, W., Forbes, S., Franchin, L., Frank, M. C., Geraci, A., Hamlin, J. K., … & Zettersten, M. (2022). Improving the generalizability of infant psychological research: The ManyBabies model. Behavioral and Brain Sciences, 45, E35. doi:

Tan, E., &  Hamlin, J.K. (2022). Infants’ Neural Responses to Helping and Hindering Scenarios. Developmental Cognitive Neuroscience, 54.

Tan, E., & Hamlin, J.K. (2022). Mechanisms of social evaluation in infancy: A preregistered exploration of infants’ eye-movement and pupillary responses to prosocial and antisocial events. Infancy, 27(2),

Coles, N.A., Hamlin, J.K., Sullivan, L.L., Parker, T.H., & Altschul, D. (2022). Build up big-team science. Nature, 601, 505-507.


Woo, B. M., Tan, E., & Hamlin, K. (2021). Theory of Mind in Context: Mental State Representations for Social Evaluation. Behavioural and Brain Sciences, 44,

Lucca, K., Capelier-Mourguy, A., Byers-Heinlein, K., Frank, M.C. … Yuen, F., …Hamlin, J.K. (2021). Infants’ social evaluation of helpers and hinderers: A large-scale, multi-lab, coordinated replication study. Stage 1 Registered Report. Developmental Science.

Tsoi, L., Hamlin, J. K., Waytz, A., Baron, A. S., Young, L. (2021). A cooperation advantage for theory of mind in children and adults. Social Cognition, 39(1), 19040.

Byers-Heinlein, K., …Hamlin, J.K. … (2021). A multi-lab study of bilingual infants: Exploring the preference for infant-directed speech. Advances in Methods and Practices in Psychological Science, 4(1), 1-30.


Byers-Heinlein, K., Bergmann, C., Davies, C., Frank, M.C., Hamlin, J.K., Kline, M., Kominsky, J.F., Kosie, J.E., Lew-Williams, C., Liu, L., Mastroberardino, M., Singh, L., Waddell, C.P.G., Zettersten, M., & Soderstrom, M. (2020). Building a collaborative Psychological Science: Lessons Learned from ManyBabies 1. Canadian Psychology/Psychologie Canadienne, 61(4), 349-363.

Tan, E., Mikami, A. Y., Luzhanska, A., & Hamlin, J. K. (2020). The homogeneity and heterogeneity of moral functioning in preschool. Child Development.

Many Babies Consortium, with Bergelson, E., Bergmann, C., Byers-Heinlein, K., Cristia, A., Cusack, R., Dyck, K.,…Hamlin, J.K., … & Yurovsky, D. (2020). Quantifying sources of variability in infancy research using the infant-directed speech preference. Advances in Methods and Practices in Psychological Science, 3(1), 24-52.

*my lab was heavily involved in all stages of this project; authorship alphabetical


Koenig, M. A., Tiberius, V., & Hamlin, J. K. (2019). Children’s judgments of epistemic and moral agents: From situations to intentions. Perspectives on Psychological Science, 14(3),

McAuliffe, K., Bogese, M., Chang, L., Andrews, C., Mayer, T., Faranda, A., Hamlin, J.K., & Santos, L. (2019). Do dogs prefer helpers in an infant-based social evaluation task?
Frontiers in Psychology, 10, 591. doi: 10.3389/fpsyg.2019.00591

Lucca, K., Hamlin, J.K., & Somerville, J.A. (2019). Early moral cognition and behavior [Editorial]. Frontiers in Psychology. doi: 10.3389/fpsyg.2019.02013


Van de Vondervoort, J. W., & Hamlin, J. K. (2018). Preschoolers focus on others’ intentions when forming sociomoral judgments. Frontiers in Psychology, 9, 1851. doi:10.3389/fpsyg.2018.01851.

Van de Vondervoort, J. W., & Hamlin, J. K. (2018). Infants’ and Young Children’s Preferences for Prosocial over Antisocial Others. Human Development 61(4-5), 214-231.
Online first: doi: 10.1159/000492800.

Tan, E., Mikami, A., & Hamlin, J.K. (2018). Do infant sociomoral evaluation and action studies predict preschool social and behavioral adjustment? Journal of Experimental Child
Psychology, 176, 39-54. doi: 10.1016/j.jecp.2018.07.003

Steckler, C.M., Liberman, Z., Van de Vondervoort, J.W., Slevinsky, J., Le, D., & Hamlin, J.K. (2018). Feeling out a link between feeling and infant sociomoral evaluation. British Journal of Developmental Psychology. doi: 10.1111/bjdp.12232

Van de Vondervoort, J.W., Aknin, L. B., Kushnir, T., Slevinsky, J., & Hamlin, J. K. (2018). Selectivity in toddlers’ behavioral and emotional reactions to prosocial and antisocial others. Developmental Psychology, 54(1), 1-14doi: 10.1037/dev0000404

 Van de Vondervoort, J.W., & Hamlin, J. K. (2018). The early emergence of sociomoral evaluation: Infants prefer prosocial others. Current Opinion in Psychology, 20, 77-81. doi: 10.1016/j.copsyc.2017.08.014

Aknin, L. B.,Van de Vondervoort, J.W., & Hamlin, J. K. (2018) Positive Feelings Reward and Promote Prosocial Behavior. Current Opinion in Psychology, 20, 55-59. doi: 10.1016/j.copsyc.2017.08.017


Steckler, C.M., Hamlin, J.K., Miller, M., King, D., Kingstone, A. (2017). Moral judgment by the disconnected left and right cerebral hemispheres: A split-brain investigation. Royal Society Open Science, 4(7): 170172. © 2017 The Royal Society. doi: 10.1098/rsos.170172

Hamlin, J.K. (2017). Is psychology moving in the right direction? An analysis of the evidentiary value movement. Perspectives on Psychological Science, 12(4): 690-693. © 2017 Sage Publishing. doi: 10.1177/1745691616689062

Van de Vondervoort, J.W. & Hamlin, J. K. (2017). Preschoolers’ social and moral judgments of third-party helpers and hinderers align with infants’ social evaluations. Journal of Experimental Child Psychology, 164, 136-151. © 2017 Elsevier Inc. doi: 10.1016/j.jecp.2017.07.004

Woo, B.M., Steckler, C.M., Le, D.T., & Hamlin, J. K. (2017). Social Evaluation of Intentional, Truly Accidental, and Negligently Accidental Helpers and Harmers by 10-months-old Infants. Cognition, 168, 154-163. © 2017 Elsevier B.V. doi: 10.1016/j.cognition.2017.06.029

Pun, A., Ferera, M., Diesendruck, G., Hamlin, J.K., & Baron, A. S. (2017). Foundations of Infants’ Social Group Evaluations. Developmental Science. © 2017 John Wiley & Sons Ltd. doi: 10.1111/desc.12586

Steckler, C.M., Woo, B.M., & Hamlin, J.K. (2017). The limits of early social evaluation: 9-month-olds fail to generate social evaluations of individuals who behave inconsistently. Cognition, 167, 255-265. © 2017 Elsevier B.V. 167, 255-265. doi: 10.1016/j.cognition.2017.03.018

Eason, A., Hamlin, J.K., Sommerville, J. (2017). A Survey of Common Practices in Infancy Research: Description of Policies, Consistency Across and Within Labs, and Suggestions for Improvements. Infancy, 22(4): 470-491. © 2017 International Congress of Infant Studies. doi: 10.1111/infa.12183

Frank, M. C., Bergelson, E., Bergmann, C., Cristia, A., Floccia, C., Gervain, J., Hamlin, J.K., Hannon, E. E., Kline, M., Levelt, C., Lew-Williams, C., Nazzi, T., Panneton, R., Rabagliati, H., Soderstrom, M., Sullivan, J., Waxman, S., Yurovsky, D. (2017). A collaborative approach to infant research: Promoting reproducibility, best practices, and theory-building. Infancy, 22(4): 421-435. © 2017 International Congress of Infant Studies. doi: 10.1111/infa.12182. *The Centre for Infant Cognition piloted babies for this pre-registered project.


Zhao, W., Baron, A.S., & Hamlin, J.K. (2016). Using Behavioral Consensus To Learn About Social Conventions In Early Childhood. Frontiers in Psychology, 7. © 2016 Zhao, Baron and Hamlin. Creative Commons Attribution License (CC BY). doi: 10.3389/fpsyg.2016.01510

Van de Vondervoort, J.W., & Hamlin, J.K. (2016). Evidence for intuitive morality: preverbal infants make sociomoral evaluations. Child Development Perspectives, 10(3): 143-148. ©2016 The Society for Research in Child Development. doi: 10.1111/cdep.12175


Aknin, L.A., Broesch, T., Hamlin, J. K., & Van de Vondervoort, J. W. (2015). Prosocial Behavior Leads to Happiness in a Small-Scale Rural Society. Journal of Experimental Psychology: General, 144(4), 788-95. © 2015 American Psychological Associations. doi: 10.1037/xge0000082

Hamlin, J.K. (2015). The case for social evaluation in preverbal infants: Gazing toward one’s goal drives infants’ preferences for Helpers over Hinderers in the hill paradigm. Frontiers in Psychology, 5. © Hamlin. Creative Commons Attribute License (CC BY) doi: 10.3389/fpsyg.2014.01563


Aknin, L.B., Fleerackers, A. L., & Hamlin, J. K. (2014). Can third-party observers detect the emotional rewards of generous spending? Journal of Positive Psychology, 9(3): 198 – 203. © 2014 Taylor & Francis Group, LLC (Routledge). doi: 10.1080/17439760.2014.888578.

Earp, B. D., Everett, J.A.C., Madva, E. N., & Hamlin, J.K. (2014). Out, damned spot: Can the “MacBeth Effect” be replicated? Basic and Applied Social Psychology, 36, 91-98. © 2014 Taylor & Francis Group, LLC (Routledge). doi: 10.1080/01973533.2013.856792

Hamlin, J.K. (2014). Context-dependent social evaluation in 4.5-month-old human infants: The role of domain-general versus domain-specific processes in the development of social evaluation. Frontiers in Psychology, 5. © 2014 Hamlin. Creative Commons Attribute License (CC BY) doi: 10.3389/fpsyg.2014.00614

Hamlin, J.K., & Baron, A.S. (2014). Agency attribution in infancy: Evidence for a negativity bias. PLoS ONE, 9(5): e96112. © Hamlin, Baron. Creative Commons Attribute License. doi: 10.1371/journal.pone.0096112


Hamlin, J.K. (2013a). Moral judgment and action in preverbal infants and toddlers: Evidence for an innate moral core. Current Directions in Psychological Science, 22(3): 186 – 193. © 2013 Sage Publications. doi: 10.1177/0963721412470687

Hamlin, J.K. (2013b). Failed attempts to help and harm: Intention versus outcome in preverbal infants’ social evaluations. Cognition, 128(3): 451 – 474. © 2013 Elsevier B.V. doi: 10.1016/j.cognition.2013.04.004

Hamlin, J.K., Mahajan, N., Liberman, Z. & Wynn, K. (2013). Not like me = bad: Infants prefer those who harm dissimilar others. Psychological Science, 24(4): 589 – 594. © 2013 Sage Publications. doi:10.1177/09056797612457785

Hamlin, J.K., Ullman, T., Tenenbaum, J., Goodman, N., & Baker, C. (2013). The mentalistic basis of core social cognition: experiments in preverbal infants and a computational model. Developmental Science, 16(2): 209 – 226. © 2012 Blackwell Publishing Ltd. doi: 10.1111/desc.12017


Aknin, L.B., Hamlin, J.K., & Dunn, E. W. (2012). Giving leads to happiness in young children. PLoS ONE, 7(6): e39211. ©2012 Aknin et al. Creative Commons Attribute License (CC BY). doi: 10.1371/journal.pone.0039211.

Hamlin, J.K., & Wynn, K. (2012). Who knows what’s good to eat? Infants fail to match the food preferences of antisocial others. Cognitive Development, 27(3): 227 – 239. © 2012 Elsevier Ltd. doi: 10.1016/j.cogdev.2012.05.005.


Hamlin, J.K., Wynn, K., Bloom, P., & Mahajan, N. (2011). How infants and toddlers react to antisocial others. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 108(5): 19931 – 19936. © 2011 Proceedings of the National Academy of Sciences of The United States of America. doi: 10.1073/pnas.1110306108

Hamlin, J.K. & Wynn, K. (2011). Young infants prefer prosocial to antisocial others. Cognitive Development, 26(1): 30 – 39. © 2011 Elsevier Inc. doi: 10.1016/j.cogdev.2010.09.001

2010 & prior

Hamlin, J.K., Wynn, K., Bloom, P. (2010). 3-month-olds show a negativity bias in social evaluation. Developmental Science, 13(6): 923 – 939. © 2010 Blackwell Publishing Ltd. doi: 10.1111/j.1467-7687.2010.00951.x

Hamlin, J.K., Newman, G. E., & Wynn, K. (2009).  8-month-old infants infer unfulfilled goals, despite ambiguous physical evidence. Infancy. 14(5): 579 – 590. © 2009 Taylor & Francis Group, LLC. doi:10.1080/15250000903144215.

Hamlin, J.K., Hallinan, E.V., & Woodward, A.L. (2008). Do as I do: 7-month old infants selectively reproduce others’ goals. Developmental Science. 11(4): 487 – 494. ©2008 Blackwell Publishing Ltd. doi: 10.1111/j.1467-7687.2008.00694.x

Hamlin, J.K., Wynn, K., & Bloom, P. (2007). Social evaluation by preverbal infants. Nature, 450, 557 – 559. © 2007 Nature Publishing Group.  doi:10.1038/nature06288



Hamlin, J.K., & Sitch, M. (in press). Understanding and evaluating the moral world in infancy. In Tamis-Lemonda, C. & Lockman, J. (Eds.), Handbook of Moral Development.

Hamlin, J.K., & Tan, E. (2020). The emergence of moral responses and sensitivity. In L. A. Jensen (Eds.), Oxford Handbook of Moral Development: An Interdisciplinary Perspective (pp. 1-27). Oxford, England: Oxford University Press. doi: 10.1093/oxfordhb/9780190676049.013.15

Van de Vondervoort, J.W., & Hamlin, J.K. (2018). The infantile roots of sociomoral evaluations. In K. Gray & J. Graham (Eds.), Atlas of Moral Psychology (pp. 402-412). New York: Guilford Press.

Van de Vondervoort, J. W., & Hamlin, J. K. (2018). Moral development in humans. In A. Zimmerman, K.  Steckler, C.M., & Hamlin, J.K. (2016). ‘Theories of moral development’. In H. Miller (Ed.) Encyclopedia of theory in psychology. Sage Reference. Submission 9 pages.

Hamlin, J.K., & Steckler, C.M. (2015). The moral infant: On the roots of moral reasoning and behavior in the first two years, in Emerging Trends in the Social and Behavioral Sciences. R. Scott & S. Kosslyn (Eds.), Hoboken, NJ: John Wiley and Sons. Submission 9 pages.

Hamlin, J.K. (2015). The infantile origins of our moral brains. In J. Decety & T. Wheatley (Eds.), The moral brain: A multidisciplinary perspective. Pp 105-122. Cambridge, MA: MIT Press.

Hamlin, J.K. (2015). ‘Does the infant possess a moral concept?’. In E. Margolis & S. Laurence (Eds.), The Conceptual Mind: New Directions in the Study of Concepts. Pp 477-518. Cambridge, MA: MIT Press.

Hamlin, J.K. (2013). The origins of human morality: Complex sociomoral evaluations by preverbal infants. In J. Decety, & Y. Christen (Eds.), Research and Perspectives in Neurosciences. Pp 165-188. Switzerland: Springer International Publishing.

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