Department of Psychology
University of Virginia
Humans are remarkably social and cooperative. We gain immensely from living in groups by coordinating efforts to acquire food, defending ourselves against predators, assisting one another with child care, and so forth. It is argued that this ‘ultra-cooperative’ nature of humans accounts in large part for our success as a species (Tomasello, 2009). However, although individuals benefit by being part of a group, it may be in each individual’s interest to be selfish, and in the long term, such selfishness can lead to the breakdown of cooperation.
Yet human cooperation is universal. Even young children, who have limited socialization experiences, demonstrate remarkable prosocial and cooperative propensities, and do so across diverse cultures (Callaghan et al., 2011; Warneken & Tomasello, 2009). Thus, from early on, humans are equipped with psychological capacities that enhance their ability to cooperate (Fessler & Haley, 2003). My research examines these psychological capacities in early development. In other words, I ask: What motivates even young children to be prosocial rather than purely self-interested?
One important answer lies in emotions. According to the functionalist view of emotions, emotions motivate behaviors of adaptive import (Darwin, 1872). For instance, fear draws our attention to perceived threats and prepares the body to fight or escape when faced with danger. When emotions serve these basic survival functions, they are known as basic emotions (Plutchik, 1980). Social emotions, on the other hand, coordinate our social interactions and thus serve to regulate relationships and maintain group cohesion – which have been just as critical for human survival and success as navigating physical threats (Keltner & Haidt, 1999). I propose that social emotions underlie a great deal of the prosocial and cooperative behaviors that we see in young children. Here, I review some of my prior and current work in support of this proposal. In particular, I review work on three social-emotional mechanisms that promote prosocial behavior and help maintain cooperation from early in ontogeny: sympathy, guilt, and forgiveness.
Sympathy
Sympathy, or the feeling of concern for a person in need, is a crucial motivator of prosocial behavior (Eisenberg & Miller, 1987; Eisenberg, Shea, Carlo, & Knight, 1991; Hoffman, 2000). Sympathy is related to but distinct from empathy, which is the affective response that stems from comprehending another’s emotional state and is similar to what the other is feeling. Thus, whereas empathy is an emotional mechanism that allows one to feel as the other feels, sympathy is an other-directed emotional response that involves feelings of sorrow or concern for the other; as such, sympathy more than empathy is thought to motivate prosocial behavior (Eisenberg et al., 1991; Jordan, Amir, & Bloom, 2016).
Decades of research suggest that adults and even young children show concern for those in distress. For instance, when 2-year-old children see someone in pain after bumping her knee, they show facial and verbal expressions of concern, and this concern correlates with their subsequent helping or comforting behavior towards the victim (Eisenberg, Spinrad, & Sadovsky, 2006; Zahn-Waxler, Radke-Yarrow, Wagner, & Chapman, 1992).
Importantly, in order to be a reliable social motivator, sympathy needs to be more than simply a response to cues of distress (Vaish, 2016). First, it needs to be multi-determined, that is, elicited in response to whatever cues are available, even in the absence of overt distress. This enables one to sympathize flexibly across various types of situations and victims (Hoffman, 2000). Second, it needs to be context-dependent, that is, regulated based on context. After all, sympathy and prosocial behavior can be cognitively, emotionally, and materially costly (Hodges & Klein, 2001; Zahn-Waxler & Hulle, 2012). Moreover, not all contexts require equal sympathy; in competitive situations, for instance, it might be advantageous to sympathize more with members of one’s in-group than out-group. It is thus important for sympathy to be both multi-determined and context-dependent.
In a series of studies, my colleagues and I have demonstrated that sympathy checks both of these boxes from early in ontogeny. In one study (Vaish, Carpenter, & Tomasello, 2009; procedure adapted from Hobson, Harris, García-Pérez, & Hobson, 2009), 1.5- and 2-year-old children witnessed one individual causing harm to another individual, such as tearing a picture she had drawn. Importantly, the victim did not show any emotion; rather, she maintained a neutral expression during the transgression. We found that children at both ages showed greater concern for the victim when she was harmed than in a comparison condition in which she was not harmed. Children also subsequently showed greater prosocial behavior (helping, sharing, or comforting) towards the victim in the Harm than the No Harm case. Moreover, the degree of individual children’s concern was correlated with their subsequent prosocial behavior, suggesting that their concern motivated their prosocial behavior. This work and similar findings from subsequent work (e.g., Chiarella & Poulin-Dubois, 2015; Vaish, Missana, & Tomasello, 2011) suggest that children’s sympathy is multi-determined – elicited not only in response to overt distress cues but, in the absence of overt distress, also in response to situational cues. Sympathy is thus multi-determined from early in development.
In a second study, my colleagues and I explored whether children’s sympathy for distressed others is also context-dependent (Hepach, Vaish, & Tomasello, 2012b). Here, we examined whether 3-year-old children show less concern when an individual displays unjustified distress, i.e., distress that is not justified by the situation. We found that 3-year-old children showed greater concern for an adult displaying justified distress (his hand was caught in a box) than the identical but unjustified distress (his sleeve was caught in the box). Children also subsequently helped the justifiably distressed adult more quickly. Moreover, the more concern they showed, the more quickly they helped the adult, again suggesting that their concern motivated their helping. Thus, children’s sympathy varied based on whether an individual’s distress was ‘reasonable’ or ‘appropriate’ within the context. Subsequent work has shown that this ability to sympathize with justified more than unjustified distress emerges between 15 and 18 months of age (Chiarella & Poulin-Dubois, 2013). Thus, sympathy is context-dependent from a remarkably early age.
Together, sympathy that is both reliably elicited and flexibly modulated provides young children with a powerful and sophisticated motivator of prosocial behavior towards victims of harm.
Guilt
A fundamental requirement for safeguarding cooperation is that when a cooperative interaction breaks down, it must be repaired. The emotion of guilt motivates part of this repair. Guilt is the aversive emotion that follows the realization that one has harmed someone (Nelissen & Zeelenberg, 2009). It is argued to motivate reparative and prosocial behaviors, thus playing a vital role in regulating social interactions. For instance, transgressors who feel guilt generally express remorse, such as by apologizing and expressing the desire to repair (Fessler & Haley, 2003; Keltner, 1995; Zahn-Waxler & Kochanska, 1990). Additionally, guilt focuses a transgressor’s attention on the harm she or he has caused, inflicts subjective discomfort, and crucially, motivates the transgressor to make amends (Hoffman, 1982). This in turn repairs damage to the relationship (Baumeister, Stillwell, & Heatherton, 1994). Indeed, adults who have harmed someone (and so presumably feel guilt) are more likely to later help that individual than adults who have not caused harm (Brock & Becker, 1966; Ketelaar & Au, 2003).
In recent work, my colleagues and I have demonstrated a very similar phenomenon in young children (Vaish, Carpenter, & Tomasello, 2016). Our starting point was the conceptualization of guilt as consisting of two components: concern for a victim of harm and the awareness that one is responsible for causing that harm. Neither component is by itself sufficient; rather, the two together give rise to guilt (Hoffman, 1976, 1982). We set out to assess whether children show more guilt-like behaviors (verbal and physical repair) in a guilt-relevant situation than in similar situations that are not guilt-relevant. Specifically, we compared children’s reparative behavior after they accidentally caused harm to another person (guilt condition), someone else caused harm to that person (sympathy condition), or children or someone else caused the same outcome but in a non-harmful context. We found that 3-year-olds (but not 2-year-olds) showed greater verbal and physical reparative behavior in the guilt condition than in the other conditions. The 2-year-olds showed a general effect of sympathy (greater repair when the person was harmed, regardless of whether they or someone else caused the harm). Importantly, however, children’s looking behavior did reveal that both 2-year-olds and 3-year-olds tracked who caused the outcome (they or someone else) and also tracked whether the outcome was harmful or not. Thus, even 2-year-olds were sensitive to both of the factors comprising guilt, but only by 3 years did children’s verbal and physical reparative behaviors show a guilt-specific effect.
In a different approach to studying early guilt, we examined whether after harming someone, children are especially motivated to repair the harm themselves – because they recognize that they need to fix the relationship that they damaged (Hepach, Vaish, & Tomasello, 2017). For this study, we measured children’s pupil dilation as an index of their physiological arousal (see Hepach, 2017; Hepach, Vaish, Müller, & Tomasello, in press; Hepach & Westermann, 2016). We found that among both 2-year-olds and 3-year-olds, arousal decreased when they were able to repair the harm that they had caused someone, but remained high if someone else repaired the harm that the children had caused. However, when children had not caused the damage, then their arousal was similarly reduced when they or someone else repaired it. Thus, as bystanders (when children presumably feel sympathy but not guilt), children are primarily motivated to see a person in need be helped regardless of who provides the help (see also Hepach, Vaish, & Tomasello, 2012a). However, guilt alters this motivation such that children not only want the other to be helped but also want to provide the help themselves – arguably as a way of repairing and showing commitment to the disrupted relationship.
Thus, by 3, and perhaps even 2 years of age, children recognize when they have caused harm and are motivated to repair that harm and restore their ruptured relationships. Of course, we did not directly measure the emotion of guilt in these studies; indeed, complex emotions such as guilt (which have no single, identifiable facial expression) are extremely challenging to measure directly, particularly in such young children, whose verbal and introspective capacities are limited. Nonetheless, based on the behavioral and physiological arousal patterns that we observed in our studies, we propose that the experience of guilt (or something close to it) helps maintain cooperation from early in development (see Vaish, 2018).
In addition to examining when children begin to experience guilt, my colleagues and I have also examined how children respond to others’ displays of guilt. A functionalist view of emotions holds that emotions serve vital functions not only when they are experienced but also when they are displayed. In particular, others’ emotion displays help us identify their emotions, beliefs, and intentions, and thus help us figure out who is committed to us and unlikely to cheat us (Keltner, 2009; Nesse, 1990). Guilt displays are one prime example of this phenomenon. Displaying guilt after a transgression serves appeasement functions by communicating vital information to victims and bystanders. It communicates that the transgressor is also suffering, that the transgressor did not mean harm and is generally not the kind of person who means harm, and that the transgressor intends to make amends and behave more appropriately in the future (Keltner & Anderson, 2000; Leary, Landel, & Patton, 1996; McGraw, 1987). A remorseful transgressor thus elicits sympathy, forgiveness, and reduced punishment from both the victim and bystanders (Darby & Schlenker, 1989; Goffman, 1967).
Indeed, even young children (as young as 4 years of age) punish and blame transgressors less, and like them more, if they apologized than if they did not apologize (Darby & Schlenker, 1982, 1989; Smith, Chen, & Harris, 2010). Moreover, children of this age judge situations in which a transgressor apologized as better and more just than ones in which the transgressor was unapologetic (Wellman, Larkey, & Somerville, 1979). However, from an early age, children are frequently told by their caregivers and teachers to apologize (Smith, Noh, Rizzo, & Harris, 2017), even when they might not feel sorry. As a result, children’s evaluations of transgressors who explicitly apologize might be based on hearing certain key words (“sorry” or “apologize”), which they have learned are the appropriate responses after one has transgressed. It is thus critical to examine how children respond to displays of guilt when those displays do not contain explicit apologies.
Towards this end, we investigated whether and when young children are sensitive to guilt displays in the absence of apologies (Vaish, Carpenter, & Tomasello, 2011). Four- and 5-year-old children watched videos of two different transgressors engaging in minor transgressions (e.g., accidentally tearing someone’s picture). One transgressor displayed guilt (without explicitly apologizing) whereas the other transgressor did not. Children were then asked a series of questions about the two transgressors (e.g., “Whom is the victim madder at?” and “Whom do you like more?”). Five-year-olds appropriately inferred that the victim would be madder at the unremorseful transgressor and would prefer the remorseful transgressor. They also said that they would prefer to interact with the remorseful transgressor, judged the unremorseful transgressor to be meaner, and distributed more resources to the remorseful transgressor. Four-year-olds did not draw any of these inferences and distributed the resources equally between the transgressors. However, in a second study, when the remorseful transgressor provided an explicit apology, 4-year-olds did draw all of the same inferences as the 5-year-olds in the first study and distributed more resources to the remorseful transgressor. Thus, 4-year-olds are appeased by and respond positively to transgressors’ explicit apologies, but only by 5 years of age do children seem to grasp the emotions that apologies stand for, namely, guilt and remorse, and respond positively to transgressors’ displays of these emotions.
In sum, the experience of guilt (or something like it) motivates children’s reparative behavior by 2 to 3 years of age, and transgressors’ displays of guilt appease children and elicit their cooperative behavior by 4 to 5 years of age.
Forgiveness
Guilt and remorse represent one half of the repair process – the transgressor’s half. The other half is forgiveness by the victim (McCullough, 2008; Worthington, 2010). Forgiveness reestablishes a victim’s positive feelings towards transgressors, fosters reconciliation, and allows transgressors to reenter mutually beneficial relationships, thus helping to maintain cooperation (McCullough, 2008). Yet very little is known about the ontogenetic emergence of forgiveness. Recent work in my lab has delved into this topic.
In a first set of studies, we examined whether children forgive remorseful transgressors. As described above, our previous research on children’s responses to guilt displays showed that, as bystanders, 5-year-olds respond positively to remorseful transgressors, and 4-year-olds do so if the transgressor explicitly apologizes (Vaish, Carpenter, et al., 2011). Yet for a relationship to be repaired, forgiveness must come from the victim rather than a bystander. We thus investigated whether children, as the victims themselves, forgive remorseful transgressors (Oostenbroek & Vaish, in press).
We asked 4- and 5-year-old children to draw a picture with two adult experimenters. While admiring the child’s picture, the two adults accidentally tore it. One adult showed remorse whereas the other did not. Children were then asked a series of questions to examine their evaluations of and preference for the two transgressors (e.g., “Whom are you more upset with?” and “If you fell over, who do you think would help you?”). Children also distributed resources between the transgressors.
Here again we found that the 5-year-olds were more forgiving of the remorseful transgressor, as evidenced by their more positive evaluations of, preference for, and distribution of more resources to the remorseful transgressor. Four-year-olds were also more forgiving of a remorseful transgressor, but only when she explicitly apologized. These findings demonstrate that by as early as 4 years, children forgive apologetic transgressors, and that by 5 years, children do so more robustly, i.e., even with less explicit expressions of remorse.
We then asked a novel question in the forgiveness literature: Does a victim’s display of forgiveness serve important social functions? Given that forgiveness is thought to have been so important for repairing ruptured relationships and maintaining cooperation, we reasoned that a victim’s display of forgiveness might serve to signal that the victim is a reliable and valuable cooperation partner, and thus that children may value a victim who forgives than one who does not.
In a pre-registered study (Oostenbroek & Vaish, 2018), 4- and 5-year-olds watched videos showing a transgressor accidentally harming two different victims (e.g., accidentally tearing their pictures) and showing remorse in both cases. Both victims were initially upset with the transgressor. However, one of the victims then forgave the transgressor (saying, “I’ve thought about it some more. I know you’re sorry. I’m not upset with you anymore”), whereas the other victim did not forgive (“I’ve though about it some more. I know you’re sorry. I’m still really upset with you”). After watching these videos, children were asked a series of questions to assess their evaluations of the two victims and their expectations about the transgressor’s responses to the victims.
We found, as predicted, that 5-year-olds preferred the forgiver, expected the transgressor to like the forgiver more, and thought the non-forgiver would be more likely to transgress in the future. Four-year-olds did not show these robust effects. However, both 4- and 5-year-olds distributed more resources to the forgiver. This is the first evidence that from a remarkably early age, humans respond positively to victims’ displays of forgiveness and thus that displaying forgiveness may in fact be a valuable social signal.
In ongoing work on early forgiveness, we are examining the ‘valuable relationship’ hypothesis. This is the idea that if forgiveness evolved to help repair our valuable cooperative relationships, then it should be more readily elicited in cooperative than non-cooperative relationships (de Waal & Pokorny, 2005; McCullough, 2008). There is some support for this hypothesis in the adult literature. For instance, among adults, forgiveness in committed relationships leads to less anxiety and fewer negative emotions than a lack of forgiveness, whereas this difference is not apparent in non-committed relationships (Karremans, Lange, Ouwerkerk, & Kluwer, 2003). Thus, forgiveness seems to be especially important in committed relationships. We are examining whether this is a truly foundational function of forgiveness and is thus evident even in early ontogeny. Specifically, we are examining whether 4- and 5-year-old children are more forgiving of transgressors who belong to their own group (in-group members) than of transgressors who belong to a different group (out-group members). If forgiveness is especially important in valuable relationships, then children should more readily forgive and be more willing to reconcile with the in-group transgressor than the out-group transgressor.
All in all, our recent and ongoing work on forgiveness has begun to demonstrate that the capacity to forgive remorseful transgressors as well as to value forgiving victims emerges during the preschool years. These sophisticated capacities allow for the repair of ruptured relationships with valuable cooperation partners.
Conclusion
I have reviewed here three distinct but related lines of my prior and current research. This body of work shows that from a surprisingly young age, children are emotionally responsive to ruptured cooperative interactions and deeply involved in repairing such interactions. By ages 2 to 3 years, when children see someone being harmed, they show concern for that individual, and when they cause harm to someone, they show guilt-like responding in the form of heightened motivation to repair the harm. By ages 4 to 5 years, they have the ability to forgive transgressors who display remorse, and they value victims who forgive (and thus repair broken cooperative relationships) over victims who do not forgive. All of these capacities together enable children to actively participate in and contribute to the cooperation that has been so vital to humans’ survival and success.
Many questions remain, of course. Why, for instance, do the experience and expression of concern and guilt emerge earlier in development (at 2 to 3 years) than the appreciation of others’ displays of such emotions (at 4 to 5 years)? Do our findings on the emotion of guilt generalize to other social emotions (e.g., embarrassment, pride, or gratitude)? Do children always respond to a transgressor’s remorse with forgiveness and respond positively to a forgiving victim, or are there some instances in which forgiveness is not deemed the most appropriate response (such as when a transgressor repeatedly or egregiously transgresses)? These are critical questions that my collaborators and I hope to address in future research as we aim to expand our understanding of human cooperation and its early emotional mechanisms.
References
Baumeister, R. F., Stillwell, A. M., & Heatherton, T. F. (1994). Guilt: An interpersonal approach. Psychological Bulletin, 115, 243-267.
Brock, T. C., & Becker, L. A. (1966). “Debriefing” and susceptibility to subsequent experimental manipulations. Journal of Experimental Social Psychology, 2, 314-323.
Callaghan, T., Moll, H., Rakoczy, H., Warneken, F., Liszkowski, U., Behne, T., & Tomasello, M. (2011). Early social cognition in three cultural contexts. Monographs of the Society for Research in Child Development, 76(2), i-142.
Chiarella, S. S., & Poulin-Dubois, D. (2013). Cry babies and Pollyannas: Infants can detect unjustified emotional reactions. Infancy, 18, E81-E96.
Chiarella, S. S., & Poulin-Dubois, D. (2015). “Aren’t you supposed to be sad?” Infants do not treat a stoic person as an unreliable emoter. Infant Behavior and Development, 38, 57-66.
Darby, B. W., & Schlenker, B. R. (1982). Children’s reactions to apologies. Journal of Personality and Social Psychology, 43, 742-753.
Darby, B. W., & Schlenker, B. R. (1989). Children’s reactions to transgressions: Effects of the actor’s apology, reputation and remorse. British Journal of Social Psychology, 28, 353-364.
Darwin, C. (1872). The expression of the emotions in man and animals. New York, NY: Philosophical Library.
de Waal, F. B. M., & Pokorny, J. J. (2005). Primate conflict and its relation to human forgiveness. In E. L. Worthington (Ed.), Handbook of forgiveness (pp. 17-32). New York, NY: Routledge.
Eisenberg, N., & Miller, P. A. (1987). The relation of empathy to prosocial and related behaviors. Psychological Bulletin, 101, 91-119.
Eisenberg, N., Shea, C. L., Carlo, G., & Knight, G. P. (1991). Empathy-related responding and cognition: A “chicken and the egg” dilemma. In W. Kurtines & J. Gewirtz (Eds.), Handbook of moral behavior and development, Vol. 2: Research (pp. 63-88). Hillsdale, NJ: Lawrence Erlbaum Associates.
Eisenberg, N., Spinrad, T. L., & Sadovsky, A. (2006). Empathy-related responding in children. In M. Killen & J. G. Smetana (Eds.), Handbook of moral development (pp. 517-549). Mahwah: Lawrence Erlbaum Associates.
Fessler, D. M. T., & Haley, K. J. (2003). The strategy of affect: Emotions in human cooperation. In P. Hammerstein (Ed.), Genetic and Cultural Evolution of Cooperation (pp. 7-36). Cambridge, MA: MIT Press.
Goffman, E. (1967). Interaction ritual: Essays on face-to-face behavior. Garden City, NY: Anchor.
Hepach, R. (2017). Prosocial arousal in children. Child Development Perspectives, 11, 50-55.
Hepach, R., Vaish, A., Müller, K., & Tomasello, M. (in press). The relation between young children’s physiological arousal and their motivation to help others. Neuropsychologia.
Hepach, R., Vaish, A., & Tomasello, M. (2012a). Young children are intrinsically motivated to see others helped. Psychological Science, 23, 967-972. doi:10.1177/0956797612440571
Hepach, R., Vaish, A., & Tomasello, M. (2012b). Young children sympathize less in response to unjustified emotional distress. Developmental Psychology, 49, 1132-1138.
Hepach, R., Vaish, A., & Tomasello, M. (2017). Children’s intrinsic motivation to provide help themselves after accidentally harming others. Child Development, 88, 1251-1264.
Hepach, R., & Westermann, G. (2016). Pupillometry in infancy research. Journal of Cognition and Development, 17, 359-377. doi:10.1080/15248372.2015.1135801
Hobson, J. A., Harris, R., García-Pérez, R., & Hobson, P. (2009). Anticipatory concern: A study in autism. Developmental Science, 12, 249-263.
Hodges, S. D., & Klein, K. J. K. (2001). Regulating the costs of empathy: The price of being human. The Journal of Socio-Economics, 30, 437-452.
Hoffman, M. L. (1976). Empathy, role taking, guilt, and development of altruistic motives. In T. Lickona (Ed.), Moral development and behavior (pp. 124-143). New York: Holt, Rinehart, & Winston.
Hoffman, M. L. (1982). Development of prosocial motivation: Empathy and guilt. In N. Eisenberg (Ed.), The development of prosocial behavior (pp. 281-338). New York: Academic Press.
Hoffman, M. L. (2000). Empathy and moral development: Implications for caring and justice. Cambridge, UK: Cambridge University Press.
Jordan, M. R., Amir, D., & Bloom, P. (2016). Are empathy and concern psychologically distinct? Emotion, 16, 1107-1116.
Karremans, J. C., Lange, P. A. M. v., Ouwerkerk, J. W., & Kluwer, E. S. (2003). When forgiving enhances psychological well-being: The role of interpersonal commitment. Journal of Personality and Social Psychology, 84, 1011-1026.
Keltner, D. (1995). Signs of appeasement: Evidence for the distinct displays of embarrassment, amusement, and shame. Journal of Personality and Social Psychology, 68(3), 441-454.
Keltner, D. (2009). Born to be good: The science of a meaningful life. New York, NY: W. W. Norton & Company, Inc.
Keltner, D., & Anderson, C. (2000). Saving face for Darwin: The functions and uses of embarrassment. Current Directions in Psychological Science, 9, 187-192.
Keltner, D., & Haidt, J. (1999). Social functions of emotions at four levels of analysis. Cognition and Emotion, 13, 505-521.
Ketelaar, T., & Au, W. T. (2003). The effects of feelings of guilt on the behaviour of uncooperative individuals in repeated social bargaining games: An affect-as-information interpretation of the role of emotion in social interaction. Cognition and Emotion, 17, 429-453.
Leary, M. R., Landel, J. L., & Patton, K. M. (1996). The motivated expression of embarrassment following a self-presentational predicament. Journal of Personality, 64, 619-636.
McCullough, M. E. (2008). Beyond revenge: The evolution of the forgiveness instinct. San Francisco, CA: Jossey-Bass.
McGraw, K. M. (1987). Guilt following transgression: An attribution of responsibility approach. Journal of Personality and Social Psychology, 53, 247-256.
Nelissen, R. M. A., & Zeelenberg, M. (2009). When guilt evokes self-punishment: Evidence for the existence of a Dobby effect. Emotion, 9, 118-122.
Nesse, R. (1990). Evolutionary explanations of emotions. Human Nature, 1, 261-289.
Oostenbroek, J., & Vaish, A. (2018). Forgiveness as a social signal: Young children respond positively to those who forgive. Manuscript under review.
Oostenbroek, J., & Vaish, A. (in press). The emergence of forgiveness in young children. Child Development.
Plutchik, R. (1980). Emotion: A psychobioevolutionary synthesis. New York, NY: Harper & Row.
Smith, C. E., Chen, D., & Harris, P. L. (2010). When the happy victimizer says sorry: Children’s understanding of apology and emotion. British Journal of Developmental Psychology, 28, 727-746.
Smith, C. E., Noh, J. Y., Rizzo, M. T., & Harris, P. L. (2017). When and why parents prompt their children to apologize: The roles of transgression type and parenting style. Journal of Family Studies, 23, 38-61.
Tomasello, M. (2009). Why we cooperate. Cambridge, MA: MIT Press.
Vaish, A. (2016). Flexible concern: The development of multidetermined and context-dependent empathic responding. Child Development Perspectives, 10, 149-154.
Vaish, A. (2018). The prosocial functions of early social emotions: The case of guilt. Current Directions in Psychology, 20, 25-29.
Vaish, A., Carpenter, M., & Tomasello, M. (2009). Sympathy through affective perspective-taking and its relation to prosocial behavior in toddlers. Developmental Psychology, 45, 534-543.
Vaish, A., Carpenter, M., & Tomasello, M. (2011). Young children’s responses to guilt displays. Developmental Psychology, 47, 1248-1262.
Vaish, A., Carpenter, M., & Tomasello, M. (2016). The early emergence of guilt-motivated prosocial behavior. Child Development, 87, 1772-1782.
Vaish, A., Missana, M., & Tomasello, M. (2011). Three-year-old children intervene in third-party moral transgressions. British Journal of Developmental Psychology, 29, 124-130.
Warneken, F., & Tomasello, M. (2009). The roots of human altruism. British Journal of Psychology, 100, 455-471.
Wellman, H. M., Larkey, C., & Somerville, S. C. (1979). The early development of moral criteria. Child Development, 50, 879-873.
Worthington, E. L. (2010). The new science of forgiveness. In D. Keltner, J. Marsh, & J. A. Smith (Eds.), The compassionate instinct: The science of human goodness (pp. 62-71). New York, NY: W. W. Norton & Company.
Zahn-Waxler, C., & Hulle, C. V. (2012). Empathy, guilt, and depression: When caring for others becomes costly to children. In B. Oakley, A. Knafo, G. Madhavan, & D. S. Wilson (Eds.), Pathological altruism (pp. 321-344). New York, NY: Oxford University Press.
Zahn-Waxler, C., & Kochanska, G. (1990). The origins of guilt. In R. A. Thompson (Ed.), The Nebraska Symposium on Motivation 1988: Socioemotional development (Vol. 36, pp. 183-258). Lincoln: University of Nebraska Press.
Zahn-Waxler, C., Radke-Yarrow, M., Wagner, E., & Chapman, M. (1992). Development of concern for others. Developmental Psychology, 28, 126-136.
