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BackgroundIndividual differences in human cognitive abilities show consistently positive correlations across diverse domains, providing the basis for the trait of “general intelligence” (g). At present, little is known about the evolution of g, in part because most comparative studies focus on rodents or on differences across higher-level taxa. What is needed, therefore, are experiments targeting nonhuman primates, focusing on individual differences within a single species, using a broad battery of tasks. To this end, we administered a large battery of tasks, representing a broad range of cognitive domains, to a population of captive cotton-top tamarin monkeys (Saguinus oedipus).Methodology and ResultsUsing a Bayesian latent variable model, we show that the pattern of correlations among tasks is consistent with the existence of a general factor accounting for a small but significant proportion of the variance in each task (the lower bounds of 95% Bayesian credibility intervals for correlations between g and task performance all exceed 0.12).ConclusionIndividual differences in cognitive abilities within at least one other primate species can be characterized by a general intelligence factor, supporting the hypothesis that important aspects of human cognitive function most likely evolved from ancient neural substrates.

Research on moral psychology has frequently appealed to three, apparently consistent patterns:(1) Males are more likely to engage in transgressions involving harm than females; (2) educated people are likely to be more thorough in their moral deliberations because they have better resources for rationally navigating and evaluating complex information; (3) political affiliations and religious ideologies are an important source of our moral principles. Here, we provide a test of how four factors -gender, education, politics and religion -affect intuitive moral judgments in unfamiliar situations. Using a large-scale sample of participants (n=8778) who voluntarily logged on to the internet-based Moral Sense Test (available online at http://moral. wjh.harvard.edu), we analyzed responses to 145 unique moral and conventional scenarios that varied widely in content. Although each demographic or cultural factor sometimes yielded a statistically significant difference in the predicted direction (e.g., men giving more utilitarian judgments than women; religious individuals giving more deontological/rule-based judgments than atheists), these differences were consistently associated with extremely small effect sizes. We conclude that gender, education, politics and religion are likely to be relatively insignificant for moral judgments of unfamiliar scenarios. We discuss these results in light of current debates concerning the mechanisms underlying our moral judgments and, especially, the idea that we share a universal moral sense that constrains the range of cross-cultural variation.A wide variety of cultural and demographic factors appear to influence our morally relevant actions. In virtually every society, men commit more crimes, especially violent crimes, than women do. It has often been suggested that

Previous research with adults suggests that a catalog of minimally counterintuitive concepts, which underlies supernatural or religious concepts, may constitute a cognitive optimum, and is therefore cognitively encoded and culturally transmitted more successfully than either entirely intuitive concepts or maximally counterintuitive concepts. The current study examines whether children's concept recall similarly is sensitive to the degree of conceptual counterintuitiveness (operationalized as a concept's number of ontological domain violations) for items presented in the context of a fictional narrative. Seven-to-nine-year old children who listened to a story including both intuitive and counterintuitive concepts recalled the counterintuitive concepts containing one (Experiment 1) or two (Experiment 2) but not three (Experiment 3) violations of intuitive ontological expectations significantly more and in greater detail than the intuitive concepts, both immediately after hearing the story and one week later. We conclude that one or two violations of expectation may be a cognitive optimum for children: they are more inferentially rich and therefore more memorable, whereas three or more violations diminish memorability for target concepts. These results suggest that the cognitive bias for minimally counterintuitive ideas is present and active early in human development, near the start of formal religious instruction. This finding supports a growing literature suggesting that diverse, early- emerging, evolved psychological biases predispose humans to hold and perform religious beliefs and practices whose primary form and content is not derived from arbitrary custom or the social environment alone.

Do children believe that "everything happens for a reason?" That is, do children endorse purpose-based, teleological explanations for significant life events, as they do for social behavior, artifacts, biological properties, and natural kinds? Across three experiments, 5- to 7-year-olds (N = 80), 8- to 10-year-olds (N = 72), and adults (N = 91) chose between teleological and nonteleological accounts of significant life events and judged how helpful those accounts were for understanding an event's cause. Five- to 7-year-olds favored teleological explanations, but this preference diminished with age. Five- to 7-year-olds and 8- to 10-year-olds also found teleological explanations more helpful than did adults. Perceiving purpose in life events may therefore have roots in childhood, potentially reflecting a more general sensitivity to purpose in the social and natural worlds.