How retributive motives shape the emergence of third-party punishment across intergroup contexts.

This study examines how retributive motives-the desire to punish for the purpose of inflicting harm in the absence of future benefits-shape third-party punishment behavior across intergroup contexts. Six- to nine-year-olds (N = 151, Mage = 8.00, SDage = 1.15; 54% White, 18% mixed ethnicities, 17% Asian American; 46% female; from the USA) could punish ingroup, outgroup, or non-group transgressors by removing positive resources and allocating negative ones. Both punishments were described as retributive, yet allocating negative resources was perceived as more retributive than removing positive ones. We predicted that children would punish outgroups more so than ingroups and that this effect would be especially pronounced when punishment is perceived as particularly retributive. The results did not align with this prediction; instead, children similarly punished all agents.

Developing conceptions of forgiveness across the lifespan.

Understanding how to respond to transgressions is central to cooperation, yet little is known about how individuals understand the consequences of these responses. Accordingly, the current study explored children's (ages 5-9), adolescents' (ages 11-14), and adults' (N = 544, predominantly White, ~50% female, tested in 2021) understandings of three such responses-forgiveness, punishment, and doing nothing. At all ages, participants differentiated between the consequences of these three responses. Forgiveness was associated with more positive and fewer negative outcomes, while the opposite was true for punishment and doing nothing. With age, participants were less likely to expect positive outcomes, and this effect was strongest for punishment and doing nothing. The results of this study allow novel insights into reasoning about three important response strategies.

Children cooperate more with in-group members than with out-group members in an iterated face-to-face Prisoner's Dilemma Game.

Adults are more likely to cooperate with in-group members than with out-group members in the context of social dilemmas, situations in which self-interest is in conflict with collective interest. This bias has the potential to profoundly shape human cooperation, and therefore it is important to understand when it emerges in development. Here we asked whether 6- to 9-year-old children (N = 146) preferentially cooperate with in-group members in the context of a well-studied social dilemma, the iterated Prisoner's Dilemma Game. We assigned children to minimal groups and paired them with unfamiliar same-age and same-gender peers. Consistent with our predictions, children were more likely to cooperate with in-group members than with out-group members in this minimal group context. This finding adds to the current literature on group bias in children's prosocial behavior by showing that it affects decision making in a context that calls on strategic cooperation. In addition, our analyses revealed an effect of gender, with girls more likely to cooperate than boys regardless of the group membership of their partner. Exploring this gender effect further, we found an interaction between gender and age across condition, with older girls showing less sensitivity to the group membership of their partner than younger girls and with older boys showing more sensitivity to the group membership of the partner than younger boys. Our findings suggest that risky cooperation in the face of social dilemmas is shaped by group bias during childhood, highlighting the potentially deeply rooted ties between cooperation and parochialism in humans.

Recalling experiences of scarcity reduces children's generosity relative to recalling abundance.

Does a sense of having less or more than what one needs affect one's generosity? The question of how resource access influences prosocial behavior has received much attention in studies with adults but has produced conflicting findings. To better understand this relationship, we tested whether resource access affects generosity in the developing mind. In our preregistered investigation, we used a narrative recall method to explore how temporary, experimentally evoked states of resource abundance or scarcity affect children's sharing. In this study, 6- to 8-year-old American children (N = 148) recalled an experience of scarcity or abundance and then chose how many prizes to share with another child. We found that children in the scarce condition rated themselves as sadder, viewed their resource access as more limited, and shared fewer tokens than children in the abundant condition. Our results indicate that recalling past experiences of resource access creates distinct behavioral consequences for children and suggest that a sense of "having less" may encourage a strategy of resource conservation relative to a sense of "having more," even at a young age.

Children strategically conceal selfishness.

Can children exploit knowledge asymmetries to get away with selfishness? This question was addressed by testing 6- to 9-year-old children (N = 164; 81 girls) from the Northeastern United States in a modified Ultimatum Game. Children were assigned to the roles of proposers (who offered some proportion of an endowment) and responders (who could accept or reject offers). Both players in the Informed condition knew the endowment quantity in each trial. However, in the Uninformed condition, only proposers knew this information. In this condition, many proposers made "strategically selfish" offers that seemed fair based on the responders' incomplete knowledge but were actually highly selfish. These results indicate that even young children possess the ability to deceive others about their selfishness.

Children's judgments of interventions against norm violations: COVID-19 as a naturalistic case study.

The coronavirus pandemic has had a significant influence on social interactions, introducing novel social norms such as mask-wearing and social distancing to protect people's health. Because these norms and associated practices are completely novel, it is unknown how children assess what kinds of interventions are appropriate under what circumstances and what principles they draw on in their decisions. We investigated children's reasoning about interventions against individuals who failed to adhere to COVID-19 norms. In this pre-registered study (N = 128), 4- to 7-year-olds heard stories about a norm violator, that is, a person who refuses to wear a mask in class (COVID condition) or wear indoor shoes in class when his or her shoes are muddy (Muddy Shoes condition). Children evaluated four different interventions-giving a mask/indoor shoes (Giving), preventing the person from entering (Exclusion), throwing a paper ball at the person (Throwing), and not intervening (Doing Nothing)-in terms of their rightness, niceness, and effectiveness. We found that across measures children evaluated Giving most positively, whereas they viewed Throwing most negatively. Doing Nothing and Exclusion received mixed evaluations across measures, revealing nuanced judgments of these interventions in children. In most measures, there was no difference between the COVID and Muddy Shoes conditions, suggesting that children's evaluations are not specific to the novel COVID-19 context. Together, our results show that children dynamically evaluate each intervention, taking multiple factors into account. The current study has implications for the development of interventions against norm violations.

Children Show a Gender Gap in Negotiation.

In the United States, there is an unfortunate yet pervasive gender gap in wages: Women tend to make less than men for doing the same work. One prominent account for why this wage gap exists is that women and men negotiate differently. However, we currently do not know whether differences in negotiation are a product of extensive experience or are deeply rooted in development. Here, we brought data from children to bear on this important question. We gave 240 children between the ages of 4 and 9 years old a chance to negotiate for a bonus with a female or a male evaluator. Boys asked for the same bonus from a male and a female evaluator. Older girls, in contrast, asked for a smaller bonus from a male than a female evaluator. Our findings suggest that a gender gap in negotiation emerges surprisingly early in development, highlighting childhood as a key period for interventions.

Children favor punishment over restoration.

Why do people punish selfish behavior? Are they motivated to punish perpetrators of selfishness (retribution) or to compensate the victims of selfishness (restoration)? Developmental data can provide important insight into these questions by revealing whether punishment of selfishness is more retributive or restorative when it first emerges. Across two studies, we examined costly third-party intervention in 6- to 9-year-olds. In Study 1, children learned about a selfish actor who refused to share with a recipient. Children then chose to (1) punish the selfish actor by rejecting their payoff (retribution); (2) compensate the victim of selfishness by equalizing payoffs between the perpetrator and victim (restoration); or (3) do nothing. We found that children were more likely to punish than compensate in response to selfishness, suggesting that intervention in this context is more retributive than restorative. In Study 2, we tested third-party intervention in the face of generosity which, like selfishness, can lead to unequal outcomes. As in Study 1, children in this context could reject unequal payoffs, thereby depriving the recipient of the advantageous payoff but having no effect on the actor. Children could also use compensation in this context, equalizing the payoffs between actor and recipient. We found that children did not punish inequality that stemmed from generosity, suggesting that the retributive punishment in Study 1 was specifically targeting selfishness rather than inequality more generally. These results contribute to the debate on the function of third-party punishment in humans, suggesting that retributive motives toward selfish transgressors are privileged during ontogeny.

Children in the United States and Peru Pay to Correct Gender-Based Inequality.

We explore the developmental origins of intervention against gender-based pay inequality in 4- to 9-year-old children in the United States (N = 123; Study 1) and Peru (N = 115; Study 2), two countries characterized by different norms surrounding gender pay equity. We presented children with scenarios that featured gender-based pay inequality, and they could intervene at a cost to redistribute the earnings. We examined whether children favor equality or show gender bias in intervention depending on the direction of gender pay inequality. Across both societies, both girls and boys intervened against gender inequality regardless of its direction, a tendency that grew stronger with age. These findings suggest that despite developing in societies with existing gender pay inequalities, children strongly privilege equality.

Children are more forgiving of accidental harms across development.

Forgiveness is a powerful feature of human social life, allowing for the restoration of positive cooperative relationships. Despite its importance, we know relatively little about how forgiveness develops during early life and the features that shape forgiveness decisions. Here, we investigated forgiveness behavior in children aged 5-10 years (N = 257) from the United States, varying transgressor intent and remorse in a behavioral task that pitted punishment against forgiveness. We found that baseline levels of forgiveness are high, suggesting that children assume the best of transgressors in the absence of information about intent and remorse. We also found age-related increases in sensitivity to intent but not remorse, such that older children are more likely to forgive accidental transgressions. Because forgiveness is an important tool in the human social toolkit, exploring the ways in which this ability develops across age can help us to better understand the early roots of human cooperation.

Fluconazole analogues with metal-binding motifs impact metal-dependent processes and demonstrate antifungal activity in Candida albicans.

Azole antifungals are an important class of antifungal drugs due to their low cost, ability to be administered orally, and broad-spectrum activity. However, their widespread and long-term use have given rise to adaptation mechanisms that render these compounds less effective against common fungal pathogens, including Candida albicans. New antifungals are desperately needed as drug-resistant strains become more prevalent. We recently showed that copper supplementation potentiates the activity of the azole antifungal fluconazole against the opportunistic fungal pathogen C. albicans. Here, we report eight new azole analogues derived from fluconazole in which one triazole group has been replaced with a metal-binding group, a strategy designed to enhance potentiation of azole antifungal activity by copper. The bioactivity of all eight compounds was tested and compared to that of fluconazole. Three of the analogues showed activity against C. albicans and two had lower levels of trailing growth. One compound, Flu-TSCZ, was found to impact the levels, speciation, and bioavailability of cellular metals.

Does nonbinding commitment promote children's cooperation in a social dilemma?

Communication is a powerful tool for promoting cooperation in adults and is considered one of the most important solutions to social dilemmas. One feature that makes communication particularly useful in cooperative contexts is that it allows people to advertise their intentions to partners. Some work suggests that adults cooperate more after making nonbinding commitments to cooperate (i.e., commitments they do not need to uphold) than when they are not allowed to communicate their intentions to their partners. However, we know little about whether nonbinding commitments play a similar role in children. We addressed this gap by testing 6- to 9-year-old children in a simultaneous version of the iterated prisoner's dilemma game. In the communication condition, children could communicate their intended decision prior to their actual choice, whereas in the silent condition, they could not communicate. Overall, children in the communication condition were no more likely to cooperate than children in the silent condition. However, in the communication condition, but not in the silent condition, children's behavior was contingent on their previous decision; they were more likely to cooperate or defect when they had previously cooperated or defected, respectively. In addition, they rarely reversed their intended decisions in the game. Our findings suggest that, although nonbinding commitment does not promote children's cooperation in general, it may encourage children to stick to their chosen strategy, perhaps for the sake of appearing consistent. More broadly, these results contribute to our emerging understanding of the ways in which children solve social dilemmas.

Children's fairness in two Chinese schools: A combined ethnographic and experimental study.

Recent research has shown that children's sense of fairness is shaped in part by cultural practices, values, and norms. However, the specific social factors that motivate children's fairness decisions remain poorly understood. The current study combined an ethnographic approach with experimental tests of fairness (the Inequity Game) in two Chinese schools with qualitatively different practices and norms. In the "University school," children received explicit moral instruction on fairness reinforced by adults when supervising children's activities. By contrast, in the "Community school," children received less formal moral education and little adult supervision during play time, but norms of cooperation and fairness emerged through informal interactions with peers and other members of the community. Contrary to our predictions, children in both schools (N = 66) rejected both disadvantageous and advantageous allocations of resources in the test trials. However, in the very first practice trials, children from the Community school tended to reject all inequalities, whereas children from the University school tended to accept inequalities. We draw on the ethnographies of the schools to interpret these results, concluding that, despite the similarities in the experimental results, different motivations and social factors likely underlie the rejection of inequality in the two schools.

Synthesis of the C3 and C1 Constitutional Isomers of Trifluorosubphthalocyanine and Their Fluorescence within MDA-MB-231 Breast Tumor Cells.

Metal tetrapyrrole macrocycles such as porphyrins and chlorins are ubiquitous in nature. Synthetic analogs, including phthalocyanines, have found applications in medicine, particularly as photosensitizers for photodynamic therapy and as fluorescent imaging probes. Tripyrrolic macrocycles, called subphthalocyanines (SPcs) with a smaller boron atom at their core, have similar potential as optical agents. We have recently reported a series of mixed fluorinated SPcs with varying aromaticity, showing that electronic absorption and emission are synthetically tunable across the far visible region, and that the inclusion of 4-12 peripheral fluorine atoms results in strong fluorescence within MDA-MB-231 breast tumor cells. Further probing this system, we report herein the synthesis and characterization of boron trifluorosubphthalocyanine chloride (F3SPc). The constitutional isomers F3SPc(C3) and F3SPc(C1) are readily separable by chromatography, and their identity and purity have been confirmed by 1H NMR, 19F NMR, HR APCI-MS, and HPLC. Unsurprisingly, these structurally similar F3SPcs have identical electronic absorption (λmax = 557 nm; tetrahydrofuran (THF)) and emission (λem = 574 nm; Φf = 0.27-0.28; THF). Strong fluorescence from MDA-MB-231 breast tumor cells was observed following treatment with F3SPc(C3) and F3SPc(C1) (50 µM F3SPc, 15 min), further highlighting the importance of even a limited number of peripheral fluorine atoms for this type of application.

Development of in-group favoritism in children's third-party punishment of selfishness.

When enforcing norms for cooperative behavior, human adults sometimes exhibit in-group bias. For example, third-party observers punish selfish behaviors committed by out-group members more harshly than similar behaviors committed by in-group members. Although evidence suggests that children begin to systematically punish selfish behavior around the age of 6 y, the development of in-group bias in their punishment remains unknown. Do children start off enforcing fairness norms impartially, or is norm enforcement biased from its emergence? How does bias change over development? Here, we created novel social groups in the laboratory and gave 6- and 8-year-olds the opportunity to engage in costly third-party punishment of selfish sharing behavior. We found that by age 6, punishment was already biased: Selfish resource allocations received more punishment when they were proposed by out-group members and when they disadvantaged in-group members. We also found that although costly punishment increased between ages 6 and 8, bias in punishment partially decreased. Although 8-y-olds also punished selfish out-group members more harshly, they were equally likely to punish on behalf of disadvantaged in-group and out-group members, perhaps reflecting efforts to enforce norms impartially. Taken together, our results suggest that norm enforcement is biased from its emergence, but that this bias can be partially overcome through developmental change.

Low-Symmetry Mixed Fluorinated Subphthalocyanines as Fluorescence Imaging Probes in MDA-MB-231 Breast Tumor Cells.

Boron subphthalocyanines (SPcs) are aromatic macrocycles that possess a combination of physical and optical properties that make them excellent candidates for application as fluorescent imaging probes. These molecules have intense electronic absorption and emission, and structural versatility that allows for specific tuning of physical properties. Herein, we report the synthesis of a series of low-symmetry fluorinated SPcs and compare them to analogous compounds with varying numbers of peripheral fluorine atoms and varied aromaticity. Across the series, with increasing addition of fluorine atoms to the periphery of the ring, a downfield chemical shift in 19F NMR and a bathochromic shift of electronic absorption were observed. Expanding the size of the aromatic ring by replacing peripheral benzo- groups with naphtho- groups prompted a far more drastic bathochromic shift to absorption and emission. Fluorescence quantum yields (Φf) proved to be sufficiently high to observe intracellular fluorescence from MDA-MB-231 breast tumor cells in vitro by epifluorescence microscopy; fluorination proved vital for this purpose to improve solubility. This report lays the groundwork for the future development of these promising SPcs for their ultimate application as near-infrared (NIR) fluorescent imaging probes in biological systems.

Another way to learn about teaching: What dogs can tell us about the evolution of pedagogy.

Kline argues that it is crucial to isolate the respective roles of teaching and learning in order to understand how pedagogy has evolved. We argue that doing so requires testing species that learn from pedagogy but that rarely teach themselves. Here, we review how one previously neglected species - domesticated dogs (Canis familiaris) - may allow researchers to do just that.

Does effort influence inequity aversion in cotton-top tamarins (Saguinus oedipus)?

The human sense of fairness entails sensitivity not just to equality, the equal division of resources, but also to merit, the relationship between an individual's share of resources and how hard they worked for their share. Recent evidence suggests that our sensitivity to equality has deep phylogenetic roots: several nonhuman animal species show an aversion to unequal reward distributions. However, the extent to which nonhuman animals share sensitivity to merit remains poorly understood, largely because previous studies have failed to properly manipulate work effort in inequity aversion tasks. Here, we tested whether cotton-top tamarins (Saguinus oedipus) would exhibit a differential response to inequity when acquiring rewards was either (1) effortful or (2) effortless. Subjects engaged in a pulling task in which they had an opportunity to deliver a disadvantageously unequal distribution of food to themselves and a partner (one piece for self, four pieces for partner). We made delivery effortful by adding a weight to the pulling handle. Critically, effort was calibrated to each individual. Results show that individuals varied markedly in their response to effort, highlighting the importance of manipulating work effort at the individual level. Overall, subjects showed little aversion to inequity. However, subjects were slightly less likely to accept inequity when doing so was effortful, although this effect was pronounced in only one individual. Our findings suggest a new method for capturing individual variation in effort and for studying the roots of the concept of merit in nonhuman animals.

Children reject inequity out of spite.

When confronted with inequality, human children and adults sacrifice personal gain to reduce the pay-offs of other individuals, exhibiting apparently spiteful motivations. By contrast, sacrifice of personal gain by non-human animals is often interpreted as frustration. Spite may thus be a uniquely human motivator. However, to date, no empirical study has demonstrated that psychological spite actually drives human behaviour, leaving the motivation for inequity aversion unclear. Here, we ask whether 4- to 9-year-old children and adults reject disadvantageous inequity (less for self, more for peer) out of spite or frustration. We show that children, but not adults, are more likely to reject disadvantageous allocations when doing so deprives their peer of a better reward (spite) than when their peer has already received the better reward (frustration). Spiteful motivations are thus present early in childhood and may be a species-specific component of humans' developing cooperative and competitive behaviour.

Why imagining what could have happened matters for children's social cognition.

Counterfactual thinking is a relatively late emerging ability in childhood with key implications for emerging social cognition and behavior.