A central challenge in moral development is learning to evaluate actions not only by their outcomes, but also by the choices available to the person who acted. The present study investigates how this capacity develops in preschool-age children. Using a child-friendly version of the trolley problem, 3- to 5-year-olds (N = 124, 51% girls) judged a protagonist who moved a barrier to protect three children from having their cookies eaten by a mean squirrel. Children typically judged this action as morally good when no better alternative was available, even when it caused harm to another child. However, they judged the same action as morally bad when a non-harmful alternative was available but not chosen. Sensitivity to the availability of alternatives increased with age, indicating developmental change in how children integrate information about outcomes and choice constraints when forming moral judgments.

We ask whether moral judgment in preschool children observes a "means principle." It is well established that young children consider both the consequences and the goals of actions when making moral judgments; much less studied is the question of whether the means used to attain a given goal also matter. By obtaining preschoolers' judgments regarding when, if ever, it is permissible for 1 person to harm another as a means, we show, across 2 experiments, that children (N = 200 across 2 studies; Mage = 5.1 yrs.) use the means principle in their moral judgments. Subjects recognized not only when a harm was being used as a means but also situated that means appropriately with respect to the correct superordinate goal. In this respect, the preschoolers in this sample are like adults across a wide range of cultures. These findings have important implications for the understanding of moral development: young children can use an agent's means, and not just her goal, to make a moral judgment. We discuss the broader issue of whether, in light of emerging evidence for the means principle, there really are any moral universals. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Are there any moral universals? Theories that view morality as culturally constructed do not necessarily anticipate finding moral universals. Theories that view morality as emerging from a “universal moral grammar” necessarily do. Yet, to date, there has not been sufficient evidence to confidently claim that any part of moral psychology is universal. However, a series of recent studies has shown that adults in over 40 countries use the same (perhaps surprising) moral rule: the “means principle.” Developmental evidence of the early emergence of the means principle would provide additional support that this principle is universal. In this paper, we indeed find that children (N=192 across 2 studies; Mage=5.1 yrs.) use the means principle in their moral judgments. This finding also has important implications for the understanding of moral development; it reveals that children can use an agent’s means, and not just her goal, to make a moral judgment.

A central canon in theory of mind research is that between the ages of three and four a drastic performance difference in children’s understanding occurs. However, the reason for the ‘three to four shift’ has yet to be settled. One account, Theory of Mind Mechanism (ToMM) theory (Leslie, 1994), posits that change in inhibitory power can account for this difference. This is supported by a recent computational implementation of the theory, showing that differences in inhibitory power can account for age differences at an aggregate level (Wang, Hemmer, & Leslie, 2019). However, as Baker et al. (2016) point out, established findings are entirely based on groupaggregated findings, yet computational and developmental processes do not take place in the ‘aggregated mind’. What remains largely unexplored is what happens at the level of the individual child. Here we combine the computational implementation of ToMM with data from Baker et al., 2016, who assessed longitudinal developmental change in Theory of Mind performance by repeated testing of individual child over the three-to-four shift period on standard ‘Sally and Anne’ false belief tasks, to obtain a cumulative record for each child. Specifically, we found that children’s age was not directly informative of developmental change in theory of mind reasoning. Instead, the main contributor to theory of mind performance at the individual learner level is inhibitory power.

Six-month-old infants can store representations of multiple objects in working memory but do not always remember the objects' features (e.g., shape). Here, we asked whether infants' object representations (a) may contain conceptual content and (b) may contain this content even if perceptual features are forgotten. We hid two conceptually distinct objects (a humanlike doll and a nonhuman ball) one at a time in two separate locations and then tested infants' memory for the first-hidden object by revealing either the original hidden object or an unexpected other object. Using looking time, we found that infants remembered the categorical identity of the hidden object but failed to remember its perceptual identity. Our results suggest that young infants may encode conceptual category in a representation of an occluded object, even when perceptual features are lost.

A striking characteristic of human thought is that we form representations about abstract kinds (Giraffes have purple tongues), despite experiencing only particular individuals (This giraffe has a purple tongue). These generic generalizations have been hypothesized to be a cognitive default, that is, more basic and automatic than other forms of generalization, including those involving quantifiers such as "all" or "most." In support of this hypothesis, children often recall quantified statements (e.g., "All/many/most bears climb trees") as generic ("Bears climb trees"), and do so more frequently than the reverse error of recalling generics as quantified. The present study provides a strong test of the generics-as-default position by testing whether even numerically quantified statements (e.g., "Five giraffes have purple tongues") are recalled as generic. Two groups of three-year-old children (N = 74) were tested: those who held a correct numerical interpretation of five ("5-knowers"), and those who did not ("non-5-knowers"). Results indicate that non-5-knowers often defaulted to the generic in recall after hearing a number (e.g., recalling "Five giraffes." as "Giraffes."), whereas 5-knowers did not. Thus, consistent with the generic-as-default hypothesis, before children have a specific numerosity assigned to "five," they display a tendency to recall numerically quantified phrases as generic.

Various theories of moral cognition posit that moral intuitions can be understood as the output of a computational process performed over structured mental representations of human action. We propose that action plan diagrams-"act trees"-can be a useful tool for theorists to succinctly and clearly present their hypotheses about the information contained in these representations. We then develop a methodology for using a series of linguistic probes to test the theories embodied in the act trees. In Study 1, we validate the method by testing a specific hypothesis (diagrammed by act trees) about how subjects are representing two classic moral dilemmas and finding that the data support the hypothesis. In Studies 2-4, we explore possible explanations for discrete and surprising findings that our hypothesis did not predict. In Study 5, we apply the method to a less well-studied case and show how new experiments generated by our method can be used to settle debates about how actions are mentally represented. In Study 6, we argue that our method captures the mental representation of human action better than an alternative approach. A brief conclusion suggests that act trees can be profitably used in various fields interested in complex representations of human action, including law, philosophy, psychology, linguistics, neuroscience, computer science, robotics, and artificial intelligence.

A robust empirical finding in theory-of-mind (ToM) reasoning, as measured by standard false-belief tasks, is that children four years old or older succeed whereas three-year-olds typically fail in predicting a person’s behavior based on an attributed false belief. Nevertheless, when the child’s own belief is undermined by increasing their subjective uncertainty about the truth, as introduced in low-demand false-belief tasks, three-year-olds can better appreciate another person’s false belief. Inhibition is believed to play a critical role in such developmental patterns. Within a Bayesian framework, using meta-data, we present the first computational implementation of inhibition, as specified by the Theory of Mind Mechanism (ToMM) model, to account for both the developmental shift from three to four years of age and the change in children’s performances between high-demand and low-demand false-belief tasks. A Bayesian framework enables us to evaluate the predictive power of the model and infer the underlying psychological parameters. Together with behavioral evidence, we discuss the critical role of inhibitory control, as specified by ToMM, in children’s theory-of-mind development.

The presumption of innocence is not only a bedrock principle of American law, but also a fundamental human right. The psychological underpinnings of this presumption, however, are not well understood. To make progress, one important task is to explain how adults and children infer the goals and intentional structure of complex actions, especially when a single action has more than one salient effect. Many theories of moral judgment have either ignored this intention inference problem or have simply assumed a particular solution without empirical support. We propose that this problem may be solved by appealing to domain-specific prior knowledge that is either built-up over the probability of prior intentions or built-in as part of core cognition. We further propose a specific solution to this problem in the moral domain: a good intention prior, which entails a rebuttable presumption that if an action has both good and bad effects, the actor intends the good effects and not the bad effects. Finally, in a series of novel experiments we provide the first empirical support - from both adults and preschool children - for the existence of this good intention prior. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Do choices about which moral actions to take cohere with subsequent judgments of their outcomes? The first set of experiments (N = 60 preschoolers and 30 adults) directly compared whether moral choices and judgments reflect distinct considerations, and whether coherence varies based on the valence of the moral scenario. Participants' responses suggested that moral principles may be applied differently for moral choices and judgments, and that harm-based situations are particularly demanding for children. To determine whether children's difficulty with harm-based situations reflects demand characteristics, a second set of experiments presented forty-three preschoolers and thirty-nine adults with a moral dilemma wherein they could choose to omit an action and maximize harm or act to minimize harm. Both age groups acted to minimize harm when caused indirectly. These results suggest that making choices about harm are not unilaterally demanding for preschoolers, but they struggle to make choices that minimize harm in a forced-choice scenario.

Although learning and development reflect changes situated in an individual brain, most discussions of behavioral change are based on the evidence of group averages. Our reliance on group-averaged data creates a dilemma. On the one hand, we need to use traditional inferential statistics. On the other hand, group averages are highly ambiguous when we need to understand change in the individual; the average pattern of change may characterize all, some, or none of the individuals in the group. Here we present a new method for statistically characterizing developmental change in each individual child we study. Using false-belief tasks, fifty-two children in two cohorts were repeatedly tested for varying lengths of time between 3 and 5 years of age. Using a novel Bayesian change point analysis, we determined both the presence and-just as importantly-the absence of change in individual longitudinal cumulative records. Whenever the analysis supports a change conclusion, it identifies in that child's record the most likely point at which change occurred. Results show striking variability in patterns of change and stability across individual children. We then group the individuals by their various patterns of change or no change. The resulting patterns provide scarce support for sudden changes in competence and shed new light on the concepts of "passing" and "failing" in developmental studies.

This study investigated the motivational and social‐cognitive foundations (i.e., inequality aversion, in‐group bias, and theory of mind) that underlie the development of sharing behavior among 3‐ to 9‐year‐old Chinese children ( N = 122). Each child played two mini‐dictator games against an in‐group member (friend) and an out‐group member (stranger) to divide four stickers. Results indicated that there was a small to moderate age‐related increase in children's egalitarian sharing with strangers, whereas the age effect was moderate to large in interactions with friends. Moreover, 3‐ to 4‐year‐olds did not treat strangers and friends differently, but 5‐ to 6‐year‐old and older children showed strong in‐group favoritism. Finally, theory of mind was an essential prerequisite for children's sharing behavior toward strangers, but not a unique predictor of their sharing with friends.

Recent studies reveal spontaneous implicit false-belief understanding in infancy. But is this early ability genuine theory-of-mind? Spontaneous tasks may allow early success by eliminating the selection-response bias thought to underlie later failure on standard (verbal) tasks. However, using anticipatory eye gaze, we find the same bias in non-verbal tasks in both preschoolers and adults. We argue that the bias arises from theory-of-mind competence itself and takes the form of a rational prior to attribute one's own belief to others. Our discussion then draws attention to a number of other inferential hallmarks of early belief-desire reasoning that together suggest it is the real deal.

Infants and adults are highly sensitive to objects' topology (geometrical invariance under stretching). Indeed, topological class information may form the essential core of object representations. We tested this hypothesis by studying 6-month-old infants, who can remember the existence of multiple objects but are limited to remembering the featural identity (e.g., shape or color) of only one object. In two experiments, after hiding two topologically distinct objects separately, we revealed one of the objects to have either changed topology, remained the same, or vanished completely. Bayes Factor analysis showed that infants remembered the topology of only one of the two hidden objects (n = 24, Experiment 1), but failed to remember anything about the other object (n =36, Experiment 2). These results contrast with the case of shape and suggest a different, more nuanced role for topological class in infants' object representation. (C) 2015 Elsevier Inc. All rights reserved.

Learning about a novel, goal-directed action is a complex process. It requires identifying the outcome of the action and linking the action to its outcome for later use in new situations to predict the action or to anticipate its outcome. We investigated the hypothesis that linking a novel action to a salient change in the environment is critical for infants to assign a goal to the novel action. We report a study in which we show that 12-month-old infants, who were provided with prior experience with a novel action accompanied with a salient visible outcome in one context, can interpret the same action as goal-directed even in the absence of the outcome in another context. Our control condition shows that prior experience with the action, but without the salient effect, does not lead to goal-directed interpretation of the novel action. We also found that, for the case of 9-month-olds infants, prior experience with the outcome producing potential of the novel action does not facilitate a goal-directed interpretation of the action. However, this failure was possibly due to difficulties with generalizing the learnt association to another context rather than with linking the action to its outcome.

Infants have a bandwidth-limited object working memory (WM) that can both individuate and identify objects in a scene, (answering 'how many?' or 'what?', respectively). Studies of infants' WM for objects have typically looked for limits on either 'how many' or 'what', yielding different estimates of infant capacity. Infants can keep track of about three individuals (regardless of identity), but appear to be much more limited in the number of specific identities they can recall. Why are the limits on 'how many' and 'what' different? Are the limits entirely separate, do they interact, or are they simply two different aspects of the same underlying limit? We sought to unravel these limits in a series of experiments which tested 9- and 12-month-olds' WM for object identities under varying degrees of difficulty. In a violation-of-expectation looking-time task, we hid objects one at a time behind separate screens, and then probed infants' WM for the shape identity of the penultimate object in the sequence. We manipulated the difficulty of the task by varying both the number of objects in hiding locations and the number of means by which infants could detect a shape change to the probed object. We found that 9-month-olds' WM for identities was limited by the number of hiding locations: when the probed object was one of two objects hidden (one in each of two locations), 9-month-olds succeeded, and they did so even though they were given only one means to detect the change. However, when the probed object was one of three objects hidden (one in each of three locations), they failed, even when they were given two means to detect the shape change. Twelve-month-olds, by contrast, succeeded at the most difficult task level. Results show that WM for 'how many' and for 'what' are not entirely separate. Individuated objects are tracked relatively cheaply. Maintaining bindings between indexed objects and identifying featural information incurs a greater attentional/memory cost. This cost reduces with development. We conclude that infant WM supports a small number of featureless object representations that index the current locations of objects. These can have featural information bound to them, but only at substantial cost.

Do victims' emotions underlie preschoolers' moral judgment abilities? Study 1 asked preschoolers (n = 72) to judge actions directed at characters who could and could not feel hurt and who did and did not cry. These judgments took into account only the nature of the action, not the nature of the victim. To further investigate how victims' emotions might impact children's moral judgments, Study 2 presented preschoolers (n = 37) with stories that varied in transgression type (Moral, Conventional, or None) and victim's reaction (Crying Present or Crying Absent). As in Study 1, children's judgments were affected primarily by transgression type, and not by emotion. In an analogous task, judgments of children with autism spectrum disorders (Study 3; n = 12) were affected by both transgression type and crying. Typically developing children's moral judgments are thus concerned primarily with action type, not with emotional displays, but the judgments of children with autism spectrum disorders can be swayed by victims' emotions.

It is now 27 years since the publication of the first article testing whether children with autism have a theory of mind (in 1985). The original study by my colleagues Alan Leslie and Uta Frith and I found that some 80% of children with autism failed this test that most typical children of 4 years old could pass. It concluded that this could not be attributed to general developmental delay or learning difficulties, because in a control group of children with Down Syndrome, some 80% of them passed. The results has been replicated dozens of times,suggesting this is a robust finding. This initial paper is considered important for 10 reasons.