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.

Having less means wanting more: Children hold an intuitive economic theory of diminishing marginal utility.

Judgments surrounding resource acquisition and valuation are ubiquitous in daily life. How do humans decide what something is worth to themselves or someone else? One important cue to value is that of resource quantity. As described by economists, the principle of diminishing marginal utility (DMU) holds that as resource abundance increases, the value placed on each unit decreases; likewise, when resources become more scarce, the value placed on each unit rises. While prior research suggests that adults make judgments that align with this concept, it is unclear whether children do so. In Study 1 (n = 104), children (ages 5 through 8) were presented with scenarios involving losses or gains to others' resources and predicted the actions and emotions of the individuals involved. Participants made decisions that aligned with DMU, e.g., expecting individuals with fewer resources to expend more effort for an additional resource than individuals with greater resources. In Study 2 (n = 104), children incorporated information about preferences when inferring others' resource valuations, showing how quantity and preference are both included in children's inferences about others' utility. Our results indicate the early emergence of an intuitive economic theory that aligns with an important economic principle. Long before formal learning on this topic, children integrate quantity and preference information to sensibly predict others' resource valuations, with implications for economic decision-making, social preferences, and judgments of partner quality across the lifespan.

"I know it's complicated": Children detect relevant information about object complexity.

Mechanistic complexity is an important property that affects how we interact with and learn from artifacts. Although highly complex artifacts have only recently become part of human material culture, they are ever-present in contemporary life. In previous research, children successfully detected complexity contrasts when given information about the functions of simple and complex objects. However, whether children spontaneously favor relevant information about an object's causal mechanisms and functions when trying to determine an object's complexity remains an open question. In Study 1, 7- to 9-year-olds and adults, but not 5- and 6-year-olds, rated information about relevant actions (e.g., the difficulty in fixing an object) as more helpful than information about irrelevant actions (e.g., the difficulty in spelling an object's name) for making determinations of mechanistic complexity. Only in Study 2, in which the relevance contrasts were extreme, did the youngest age group rate relevant actions as more helpful than irrelevant actions. In Study 3, in which participants rated the complexity of the actions themselves, participants performed differently than in the previous studies, suggesting that children in the prior studies did not misinterpret the study instructions as prompts to rate the actions' complexity. These results suggest that the ability to detect which object properties imply complexity emerges during the early school years. Younger children may be misled by features that are not truly diagnostic of mechanistic complexity, whereas older children more easily disregard such features in favor of relevant information.

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.

Trustworthiness is distinct from generosity in children.

Interpersonal trust is a key component of cooperation, helping support the complex social networks found across societies. Trust typically involves two parties, one who trusts by taking on risk through investment in a second party, who can be trustworthy and produce mutual benefits. To date, the developmental literature has focused primarily on the trustor, meaning we know little about the ontogeny of trustworthiness. Whereas trusting can be motivated by self-interest, one-shot trustworthiness is more squarely situated in the prosocial domain, involving a direct tradeoff between self-interest and others' interests. However, this raises the question of whether trustworthiness is distinct from generosity. In this preregistered study, we examine the origins of trustworthiness using an intuitive version of the Trust Game, in which a first party invests resources in a second party who can split the gains. We recruited N = 118 5-to-8 year-old American children (Mage = 6.94, n = 59 girls, 57% White, 88% of parents with bachelor's degree or higher), split between the Trustworthiness condition, where another party's investment is instrumental for obtaining greater resources, and the Generosity condition, where the other party is a passive recipient. We found that children in the Trustworthiness condition shared significantly more resources than those in the Generosity condition. Further, children in the Trustworthiness condition predicted that the first party expected them to share a greater number of resources. Overall, these results demonstrate that trustworthiness is distinct from generosity in childhood and suggest that children spontaneously grasp and engage in a key aspect of cooperation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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.

The world within: Children are sensitive to internal complexity cues.

When reasoning about the mechanisms of complex entities, it is important to consider their internal parts. Previous research has shown that young children view "insides" as critical to how objects function. However, whether children hold specific expectations regarding complex objects' insides remains an open question. Here, children (n = 378) and adults (n = 124) made internal and causal complexity judgments regarding real-world objects. In Study 1, 5- and 6-year-olds, but not 4-year-olds, succeeded at internal complexity judgments and matched complex artifacts with complex insides. All age groups succeeded at causal complexity judgments and identified complex artifacts as causally complex. Study 2 tested whether the internal complexity cues of number/area, diversity, and connections of internal parts conveyed complexity to children. The 5-year-olds were sensitive only to number/area of internal parts as a complexity cue, but the older children and adults were sensitive to all three cues plus number of parts when controlling for area (Study 3). Despite limited exposure to insides, even young school-age children hold detailed and abstract expectations concerning internal complexity.

"Wealth Makes Many Friends": Children Expect More Giving From Resource-Rich Than Resource-Poor Individuals.

Young children show social preferences for resource-rich individuals, although few studies have explored the causes underlying such preferences. We evaluate the viability of one candidate cause: Children believe that resource wealth relates to behavior, such that they expect the resource rich to be more likely to materially benefit others (including themselves) than the resource poor. In Studies 1 and 2 (ages 4-10), American children from predominantly middle-income families (n = 94) and Indian children from lower income families (n = 30) predicted that the resource rich would be likelier to share with others than the resource poor. In Study 3, American children (n = 66) made similar predictions in an incentivized decision-making task. The possibility that children's expectations regarding giving contribute to prowealth preferences is discussed.

Children employ wealth cues when predicting others' sharing.

Previous research has found that even young children accurately assign wealth labels (e.g., rich or poor) to real-world wealth symbols, such as pictures of houses. However, it is unclear whether children spontaneously consider individuals' wealth status when predicting how they will behave toward others. In Study 1, children (n = 100, ages 4-5 and 7-8) predicted that residents of "rich" houses would be likelier to share toys than residents of "poor" houses. This effect was driven by children who viewed rich-house residents as owning more toys. Study 2 (n = 50) suggested that such children were not merely associating attractive objects with attractive behaviors. Rather, it seems that they possessed a conceptual understanding of wealth, which they used to make behavioral predictions. The belief that the rich are likely to share may relate to broader wealth-based preferences and may be elicited more frequently in children who spontaneously notice others' wealth status. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Diverse Effects, Complex Causes: Children Use Information About Machines' Functional Diversity to Infer Internal Complexity.

Four studies explored the abilities of 80 adults and 180 children (4-9 years), from predominantly middle-class families in the Northeastern United States, to use information about machines' observable functional capacities to infer their internal, "hidden" mechanistic complexity. Children as young as 4 and 5 years old used machines' numbers of functions as indications of complexity and matched machines performing more functions with more complex "insides" (Study 1). However, only older children (6 and older) and adults used machines' functional diversity alone as an indication of complexity (Studies 2-4). The ability to use functional diversity as a complexity cue therefore emerges during the early school years, well before the use of diversity in most categorical induction tasks.

Defining MCI in the Framingham Heart Study Offspring: education versus WRAT-based norms.

INTRODUCTION: Psychometric definitions of mild cognitive impairment (MCI) typically use cut-off levels set at 1.5 SDs below age-adjusted and education-adjusted norms, assuming that the education adjustment accounts for premorbid abilities. However, noncognitive factors impact educational attainment, potentially leading to incorrect categorization as MCI. We examined whether using an adjustment based on reading performance [Wide Range Achievement Test (WRAT) Reading] improved MCI diagnostic accuracy. METHODS: A total of 935 Framingham Offspring (mean age, 72±5 y) underwent tests of memory, executive function, abstraction, language, and visuospatial function as part of a neuropsychological test battery. Domain-specific test scores were regressed onto age and WRAT score, or education, to define MCI. Survival analyses were used to relate baseline MCI to incident dementia. RESULTS: The 2 MCI definitions differed most for the lowest and highest education groups. The WRAT definition was more strongly associated with incident dementia for all 5 tests. MCI level abstraction performance was associated with incident dementia using the WRAT definition (HR=3.20, P=0.033), but not the education definition (HR=1.19, P=0.814). DISCUSSION: The WRAT should be considered along with the standard measure of years of education, as it may be a better surrogate marker of premorbid abilities.