Book contents
- The Cambridge Handbook of Moral Psychology
- Cambridge Handbooks in Psychology
- The Cambridge Handbook of Moral Psychology
- Copyright page
- Contents
- Figures
- Tables
- Contributors
- Preface
- 1 Modern Moral Psychology
- Part I Building Blocks
- Part II Thinking and Feeling
- Part III Behavior
- Part IV Origins, Development, and Variation
- 17 Grounding Moral Psychology in Evolution, Neurobiology, and Culture
- 18 Moral Babies? Evidence for Core Moral Responses in Infants and Toddlers
- 19 An Integrative Approach to Moral DevelopmentDuring Adolescence
- 20 Morality in Culture
- Part V Applications and Extensions
- Index
- References
18 - Moral Babies? Evidence for Core Moral Responses in Infants and Toddlers
from Part IV - Origins, Development, and Variation
Published online by Cambridge University Press: 20 February 2025
Book contents
- The Cambridge Handbook of Moral Psychology
- Cambridge Handbooks in Psychology
- The Cambridge Handbook of Moral Psychology
- Copyright page
- Contents
- Figures
- Tables
- Contributors
- Preface
- 1 Modern Moral Psychology
- Part I Building Blocks
- Part II Thinking and Feeling
- Part III Behavior
- Part IV Origins, Development, and Variation
- 17 Grounding Moral Psychology in Evolution, Neurobiology, and Culture
- 18 Moral Babies? Evidence for Core Moral Responses in Infants and Toddlers
- 19 An Integrative Approach to Moral DevelopmentDuring Adolescence
- 20 Morality in Culture
- Part V Applications and Extensions
- Index
- References
Summary
This chapter of the handbook presents a large body of evidence suggesting that, within the first year of life, infants hold both expectations about and preferences for morally good versus bad protagonists. The authors show that, across different methods, infants distinguish between morally significant acts of helping and hindering as well as between acting fairly and unfairly; they prefer the morally good actions and the morally good protagonists; and they expect others to prefer the morally good protagonists as well. Going beyond a mere valence difference, these expectations vary systematically in response to critical factors, such as the victim’s state of need, in-group/out-group membership, and an actor’s intentions. Many of the findings appear in infants 8–12 months of age, some as early as 3 months of age. Many questions remain, such as how consistent the findings are across experimenters and populations; whether the violated norm is truly moral or only a social expectation; or to what extent earliest learning guides these expectations and preferences. But overall, the evidence for budding moral distinctions in early infancy is highly compelling and provocative.
- Type
- Chapter
- Information
- The Cambridge Handbook of Moral Psychology , pp. 433 - 461Publisher: Cambridge University PressPrint publication year: 2025
References
Amir, D., & McAuliffe, K. (2020). Cross-cultural, developmental psychology: Integrating approaches and key insights. Evolution and Human Behavior, 41(5), 430–444.CrossRefGoogle Scholar
Arnett, J. J. (2008). The neglected 95%: Why American psychology needs to become less American. The American Psychologist, 63(7), 602–614.CrossRefGoogle ScholarPubMed
Aslin, R. N. (2007). What’s in a look? Developmental Science, 10(1), 48–53.CrossRefGoogle ScholarPubMed
Austin, W. (1980). Friendship and fairness: Effects of type of relationship and task performance on choice of distribution rules. Personality and Social Psychology Bulletin, 6(3), 402–408.CrossRefGoogle Scholar
Baillargeon, R., Setoh, P., Sloane, S., Jin, K., & Bian, L. (2014). Infant social cognition: Psychological and sociomoral reasoning. In Gazzaniga, M. S. & Mangun, G. R. (Eds.), The cognitive neurosciences (5th ed., pp. 7–14). Boston Review.Google Scholar
Bandura, A. (1977). Self-efficacy: Toward a unifying theory of behavioral change. Psychological Review, 84(2), 191–215.CrossRefGoogle Scholar
Baumeister, R. F., Bratslavsky, E., Finkenauer, C., & Vohs, K. D. (2001). Bad is stronger than good. Review of General Psychology, 5(4), 323–370.CrossRefGoogle Scholar
Bian, L., Sloane, S., & Baillargeon, R. (2018). Infants expect ingroup support to override fairness when resources are limited. Proceedings of the National Academy of Sciences, 115(11), 2705–2710.CrossRefGoogle ScholarPubMed
Boyd, R., & Richerson, P. J. (1992). Punishment allows the evolution of cooperation (or anything else) in sizable groups. Ethology and Sociobiology, 13(3), 171–195.CrossRefGoogle Scholar
Buon, M., Jacob, P., Margules, S., Brunet, I., Dutat, M., Cabrol, D., & Dupoux, E. (2014). Friend or foe? Early social evaluation of human interactions. PLoS ONE, 9(2), Article e88612.CrossRefGoogle ScholarPubMed
Burns, M., & Sommerville, J. (2014). “I pick you”: The impact of fairness and race on infants’ selection of social partners. Frontiers in Psychology, 5, Article 93.CrossRefGoogle ScholarPubMed
Buyukozer Dawkins, M., Sloane, S., & Baillargeon, R. (2019). Do infants in the first year of life expect equal resource allocations? Frontiers in Psychology, 10, Article 116.CrossRefGoogle ScholarPubMed
Casler, K., Terziyan, T., & Greene, K. (2009). Toddlers view artifact function normatively. Cognitive Development, 24(3), 240–247.CrossRefGoogle Scholar
Chae, J. J. K., & Song, H. (2018). Negativity bias in infants’ expectations about agents’ dispositions. British Journal of Developmental Psychology, 36(4), 620–633.CrossRefGoogle ScholarPubMed
Choi, Y., & Luo, Y. (2015). 13-month-olds’ understanding of social interactions. Psychological Science, 26(3), 274–283.CrossRefGoogle ScholarPubMed
Cowell, J. M., & Decety, J. (2015). Precursors to morality in development as a complex interplay between neural, socioenvironmental, and behavioral facets. Proceedings of the National Academy of Sciences, 112(41), 12657–12662.CrossRefGoogle ScholarPubMed
Curry, O. S., Jones Chesters, M., & Van Lissa, C. J. (2019). Mapping morality with a compass: Testing the theory of ‘morality-as-cooperation’ with a new questionnaire. Journal of Research in Personality, 78, 106–124.CrossRefGoogle Scholar
Curtin, C. M., Barrett, H. C., Bolyanatz, A., Crittenden, A. N., Fessler, D. M. T., Fitzpatrick, S., Gurven, M., Kanovsky, M., Kushnick, G., Laurence, S., Pisor, A., Scelza, B., Stich, S., von Rueden, C., & Henrich, J. (2020). Kinship intensity and the use of mental states in moral judgment across societies. Evolution and Human Behavior, 41(5), 415–429.CrossRefGoogle Scholar
Cushman, F. (2008). Crime and punishment: Distinguishing the roles of causal and intentional analyses in moral judgment. Cognition, 108(2), 353–380.CrossRefGoogle ScholarPubMed
DesChamps, T. D., Eason, A. E., & Sommerville, J. A. (2016). Infants associate praise and admonishment with fair and unfair individuals. Infancy: The Official Journal of the International Society on Infant Studies, 21(4), 478–504.CrossRefGoogle ScholarPubMed
Deutsch, M. (1975). Equity, equality, and need: What determines which value will be used as the basis of distributive justice? Journal of Social Issues, 31(3), 137–149.CrossRefGoogle Scholar
Eisenberg, N. (1986). Altruistic emotion, cognition, and behavior. Lawrence Erlbaum Associates.Google Scholar
Fantz, R. L. (1964). Visual experience in infants: Decreased attention to familiar patterns relative to novel ones. Science, 146(3644), 668–670.CrossRefGoogle ScholarPubMed
Fawcett, C., & Liszkowski, U. (2012). Infants anticipate others’ social preferences. Infant and Child Development, 21(3), 239–249.CrossRefGoogle Scholar
Feigenson, L., Dehaene, S., & Spelke, E. (2004). Core systems of number. Trends in Cognitive Sciences, 8(7), 307–314.CrossRefGoogle ScholarPubMed
Fidler, F., & Wilcox, J. (2021). Reproducibility of scientific results. In Zalta, E. N. (Ed.), The Stanford encyclopedia of philosophy (Summer 2021 ed.). https://plato.stanford.edu/archives/sum2021/entries/scientific-reproducibility/Google Scholar
Franchin, L., Savazzi, F., Neira-Gutierrez, I. C., & Surian, L. (2019). Toddlers map the word ‘good’ to helping agents, but not to fair distributors. Journal of Child Language, 46(1), 98–110.CrossRefGoogle Scholar
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.CrossRefGoogle ScholarPubMed
Geraci, A., & Surian, L. (2011). The developmental roots of fairness: Infants’ reactions to equal and unequal distributions of resources. Developmental Science, 14(5), 1012–1020.CrossRefGoogle ScholarPubMed
Gray, K., Young, L., & Waytz, A. (2012). Mind perception is the essence of morality. Psychological Inquiry, 23(2), 101–124.CrossRefGoogle Scholar
Grusec, J. E., Chaparro, M. P., Johnston, M., & Sherman, A. (2014). The development of moral behavior from a socialization perspective. In Killen, M. & Smetana, J. G. (Eds.), Handbook of moral development (2nd ed., pp. 113–134). Psychology Press.Google Scholar
Haidt, J., & Graham, J. (2007). When morality opposes justice: Conservatives have moral intuitions that liberals may not recognize. Social Justice Research, 20(1), 98–116.CrossRefGoogle Scholar
Haidt, J., Koller, S. H., & Dias, M. G. (1993). Affect, culture, and morality, or is it wrong to eat your dog? Journal of Personality and Social Psychology, 65(4), 613–628.CrossRefGoogle ScholarPubMed
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.CrossRefGoogle Scholar
Hamlin, J. K. (2013b). Failed attempts to help and harm: Intention versus outcome in preverbal infants’ social evaluations. Cognition, 128(3), 451–474.CrossRefGoogle ScholarPubMed
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, Article 614.CrossRefGoogle ScholarPubMed
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, Article 1563.CrossRefGoogle ScholarPubMed
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.CrossRefGoogle ScholarPubMed
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.CrossRefGoogle Scholar
Hamlin, J. K., & Wynn, K. (2011). Young infants prefer prosocial to antisocial others. Cognitive Development, 26(1), 30–39.CrossRefGoogle ScholarPubMed
Hamlin, J. K., Wynn, K., & Bloom, P. (2007). Social evaluation by preverbal infants. Nature, 450(7169), 557–559.CrossRefGoogle ScholarPubMed
Hamlin, J. K., Wynn, K., & Bloom, P. (2010). 3-month-olds show a negativity bias in their social evaluations. Developmental Science, 13(6), 923–929.CrossRefGoogle Scholar
Hamlin, J. K., Wynn, K., & Bloom, P. (2012). Reply to Scarf et al.: Nuanced social evaluation: Association doesn’t compute. Proceedings of the National Academy of Sciences, 109(22), E1427–E1427.CrossRefGoogle Scholar
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, 108(50), 19931–19936.CrossRefGoogle ScholarPubMed
Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? Behavioral and Brain Sciences, 33(2–3), 61–83.CrossRefGoogle ScholarPubMed
Henrich, J., & Henrich, N. (2007). Why humans cooperate: A cultural and evolutionary explanation. Oxford University Press.CrossRefGoogle Scholar
Heyes, C. (2014). False belief in infancy: A fresh look. Developmental Science, 17(5), 647–659.CrossRefGoogle ScholarPubMed
Hrdy, S. B. (2011). Mothers and others: The evolutionary origins of mutual understanding. Harvard University Press.CrossRefGoogle Scholar
Ioannidis, J. P. A. (2005). Why most published research findings are false. PLoS Medicine, 2(8), Article e124.CrossRefGoogle ScholarPubMed
Jin, K., & Baillargeon, R. (2017). Infants possess an abstract expectation of ingroup support. Proceedings of the National Academy of Sciences, 114(31), 8199–8204.CrossRefGoogle ScholarPubMed
Jin, K.-S., Houston, J. L., Baillargeon, R., Groh, A. M., & Roisman, G. I. (2018). Young infants expect an unfamiliar adult to comfort a crying baby: Evidence from a standard violation-of-expectation task and a novel infant-triggered-video task. Cognitive Psychology, 102, 1–20.CrossRefGoogle Scholar
Josephs, M., Kushnir, T., Gräfenhain, M., & Rakoczy, H. (2016). Children protest moral and conventional violations more when they believe actions are freely chosen. Journal of Experimental Child Psychology, 141, 247–255.CrossRefGoogle ScholarPubMed
Kanakogi, Y., Inoue, Y., Matsuda, G., Butler, D., Hiraki, K., & Myowa-Yamakoshi, M. (2017). Preverbal infants affirm third-party interventions that protect victims from aggressors. Nature Human Behaviour, 1(2), 1–7.CrossRefGoogle Scholar
Kanakogi, Y., Okumura, Y., Inoue, Y., Kitazaki, M., & Itakura, S. (2013). Rudimentary sympathy in preverbal infants: Preference for others in distress. PLoS ONE, 8(6), Article e65292.CrossRefGoogle ScholarPubMed
Katz, L. D. (2000). Evolutionary origins of morality: Cross-disciplinary perspectives. Imprint Academic.Google Scholar
Kidd, C., Piantadosi, S. T., & Aslin, R. N. (2012). The Goldilocks effect: Human infants allocate attention to visual sequences that are neither too simple nor too complex. PLoS ONE, 7(5), Article e36399.CrossRefGoogle ScholarPubMed
Kohlberg, L. (1969). Stage and sequence: The cognitive-developmental approach to socialization. Rand McNally.Google Scholar
Kominsky, J. F., Lucca, K., Thomas, A. J., Frank, M. C., & Hamlin, K. (2022). Simplicity and validity in infant research. Cognitive Development, 63, Article 101213.CrossRefGoogle Scholar
Köster, M., Ohmer, X., Nguyen, T. D., & Kärtner, J. (2016). Infants understand others’ needs. Psychological Science, 27(4), 542–548.CrossRefGoogle ScholarPubMed
Kuhlmeier, V., Wynn, K., & Bloom, P. (2003). Attribution of dispositional states by 12-month-olds. Psychological Science, 14(5), 402–408.CrossRefGoogle ScholarPubMed
Lamm, H., & Schwinger, T. (1980). Norms concerning distributive justice: Are needs taken into consideration in allocation decisions? Social Psychology Quarterly, 43(4), 425–429.CrossRefGoogle Scholar
Lee, Y., Yun, J. E., Kim, E. Y., & Song, H. (2015). The development of infants’ sensitivity to behavioral intentions when inferring others’ social preferences. PLoS ONE, 10(9), Article e0135588.CrossRefGoogle ScholarPubMed
Leventhal, G. S., & Michaels, J. W. (1969). Extending the equity model: Perception of inputs and allocation of reqard as a function of duration and quantity of performance. Journal of Personality and Social Psychology, 12(4), 303–309.CrossRefGoogle Scholar
Loheide-Niesmann, L., de Lijster, J., Hall, R., van Bakel, H., & Cima, M. (2021). Toddlers’ preference for prosocial versus antisocial agents: No associations with empathy or attachment security. Social Development, 30(2), 410–427.CrossRefGoogle Scholar
Lucca, K., Yuen, F., Wang, Y., Alessandroni, N., Allison, O., Alvarez, M., Axelsson, E. L., Baumer, J., Baumgartner, H. A., Bertels, J., Bhavsar, M., Byers-Heinlein, K., Capelier-Mourguy, A., Chijiiwa, H., Chin, C. S. S., Christner, N., Cirelli, L. K., Corbit, J., Daum, M. M., … Hamlin, J. K. (in press). Infants’ social evaluation of helpers and hinderers: A large-scale, multi-lab, coordinated replication study. Developmental Science.Google Scholar
Lucca, K., Pospisil, J., & Sommerville, J. A. (2018). Fairness informs social decision making in infancy. PLoS ONE, 13(2), Article e0192848.CrossRefGoogle ScholarPubMed
Malle, B. F. (1999). How people explain behavior: A new theoretical framework. Personality and Social Psychology Review, 3(1), 23–48.CrossRefGoogle ScholarPubMed
Margoni, F., & Surian, L. (2018). Infants’ evaluation of prosocial and antisocial agents: A meta-analysis. Developmental Psychology, 54(8), 1445–1455.CrossRefGoogle ScholarPubMed
Meristo, M., & Surian, L. (2013). Do infants detect indirect reciprocity? Cognition, 129(1), 102–113.CrossRefGoogle ScholarPubMed
Meristo, M., & Surian, L. (2014). Infants distinguish antisocial actions directed towards fair and unfair agents. PLoS ONE, 9(10), Article e110553.CrossRefGoogle ScholarPubMed
Mikhail, J. (2007). Universal moral grammar: Theory, evidence and the future. Trends in Cognitive Sciences, 11(4), 143–152.CrossRefGoogle ScholarPubMed
Nielsen, M., & Haun, D. (2016). Why developmental psychology is incomplete without comparative and cross-cultural perspectives. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 371(1686), Article 20150071.CrossRefGoogle ScholarPubMed
Nielsen, M., Haun, D., Kärtner, J., & Legare, C. H. (2017). The persistent sampling bias in developmental psychology: A call to action. Journal of Experimental Child Psychology, 162, 31–38.CrossRefGoogle ScholarPubMed
Nowak, M. A. (2006). Five rules for the evolution of cooperation. Science, 314(5805), 1560–1563.CrossRefGoogle ScholarPubMed
O’Gorman, R., Henrich, J., & Van Vugt, M. (2009). Constraining free riding in public goods games: Designated solitary punishers can sustain human cooperation. Proceedings of the Royal Society B: Biological Sciences, 276(1655), 323–329.CrossRefGoogle Scholar
Perner, J., & Ruffman, T. (2005). Infants’ insight into the mind: How deep? Science, 308(5719), 214–216.CrossRefGoogle ScholarPubMed
Premack, D., & Premack, A. J. (1994). Moral belief: Form versus content. In Hirschfeld, L. A. & Gelman, S. A. (Eds.), Mapping the mind: Domain specificity in cognition and culture (pp. 149–168). Cambridge University Press.CrossRefGoogle Scholar
Premack, D., & Premack, A. J. (1997). Infants attribute value to the goal-directed actions of self-propelled objects. Journal of Cognitive Neuroscience, 9(6), 848–856.CrossRefGoogle Scholar
Pun, A., Birch, S. A. J., & Baron, A. S. (2021). The power of allies: Infants’ expectations of social obligations during intergroup conflict. Cognition, 211, Article 104630.CrossRefGoogle ScholarPubMed
Rakoczy, H., Warneken, F., & Tomasello, M. (2008). The sources of normativity: Young children’s awareness of the normative structure of games. Developmental Psychology, 44(3), 875–881.CrossRefGoogle ScholarPubMed
Salvadori, E., Blazsekova, T., Volein, A., Karap, Z., Tatone, D., Mascaro, O., & Csibra, G. (2015). Probing the strength of infants’ preference for helpers over hinderers: Two replication attempts of Hamlin and Wynn (2011). PLoS ONE, 10(11), Article e0140570.CrossRefGoogle ScholarPubMed
Scarf, D., Imuta, K., Colombo, M., & Hayne, H. (2012). Social evaluation or simple association? Simple associations may explain moral reasoning in infants. PLoS ONE, 7(8), Article e42698.CrossRefGoogle ScholarPubMed
Schlingloff, L., Csibra, G., & Tatone, D. (2020). Do 15-month-old infants prefer helpers? A replication of Hamlin et al. (2007). Royal Society Open Science, 7(4), Article 191795.CrossRefGoogle Scholar
Schmidt, M. F. H., & Sommerville, J. A. (2011). Fairness expectations and altruistic sharing in 15-month-old human infants. PLoS ONE, 6(10), Article e23223.CrossRefGoogle ScholarPubMed
Scola, C., Holvoet, C., Arciszewski, T., & Picard, D. (2015). Further evidence for infants’ preference for prosocial over antisocial behaviors. Infancy, 20(6), 684–692.CrossRefGoogle Scholar
Shimizu, Y., Senzaki, S., & Uleman, J. S. (2018). The influence of maternal socialization on infants’ social evaluation in two cultures. Infancy, 23(5), 748–766.CrossRefGoogle Scholar
Sloane, S., Baillargeon, R., & Premack, D. (2012). Do infants have a sense of fairness? Psychological Science, 23(2), 196–204.CrossRefGoogle ScholarPubMed
Sommerville, J. A., Schmidt, M. F. H., Yun, J., & Burns, M. (2013). The development of fairness expectations and prosocial behavior in the second year of life. Infancy, 18(1), 40–66.CrossRefGoogle Scholar
Spelke, E. S., & Kinzler, K. D. (2007). Core knowledge. Developmental Science, 10(1), 89–96.CrossRefGoogle ScholarPubMed
Surian, L., Ueno, M., Itakura, S., & Meristo, M. (2018). Do infants attribute moral traits? Fourteen-month-olds’ expectations of fairness are affected by agents’ antisocial actions. Frontiers in Psychology, 9, Article 1649.CrossRefGoogle ScholarPubMed
Tafreshi, D., Thompson, J. J., & Racine, T. P. (2014). An analysis of the conceptual foundations of the infant preferential looking paradigm. Human Development, 57(4), 222–240.CrossRefGoogle Scholar
Tasimi, A., & Wynn, K. (2016). Costly rejection of wrongdoers by infants and children. Cognition, 151, 76–79.CrossRefGoogle ScholarPubMed
Ting, F., & Baillargeon, R. (2021). Toddlers draw broad negative inferences from wrongdoers’ moral violations. Proceedings of the National Academy of Sciences, 118(39), Article e2109045118.CrossRefGoogle ScholarPubMed
Turiel, E. (1983). The development of social knowledge: Morality and convention. Cambridge University Press.Google Scholar
Vaish, A., Grossmann, T., & Woodward, A. (2008). Not all emotions are created equal: The negativity bias in social-emotional development. Psychological Bulletin, 134(3), 383–403.CrossRefGoogle ScholarPubMed
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), 1–14.CrossRefGoogle ScholarPubMed
Wang, Y., & Henderson, A. (2018). Just rewards: 17-month-old infants expect agents to take resources according to the principles of distributive justice. Journal of Experimental Child Psychology, 172, 25–40.CrossRefGoogle Scholar
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-month-old infants. Cognition, 168, 154–163.CrossRefGoogle ScholarPubMed
Young, L., Cushman, F., Hauser, M., & Saxe, R. (2007). The neural basis of the interaction between theory of mind and moral judgment. Proceedings of the National Academy of Sciences, 104(20), 8235–8240.CrossRefGoogle ScholarPubMed
Ziv, T., & Sommerville, J. A. (2017). Developmental differences in infants’ fairness expectations from 6 to 15 months of age. Child Development, 88(6), 1930–1951.CrossRefGoogle ScholarPubMed
Ziv, T., Whiteman, J. D., & Sommerville, J. A. (2021). Toddlers’ interventions toward fair and unfair individuals. Cognition, 214, Article 104781.CrossRefGoogle ScholarPubMed