Knowledge that Transforms

The discovery of words in continuous speech is one of the first challenges faced by infants during language acquisition. This process is partially facilitated by statistical learning, the ability to discover and encode relevant patterns in the environment. Here, we used an electroencephalogram (EEG) index of neural entrainment to track 6-month-olds’ ( N = 25) segmentation of words from continuous speech. Infants’ neural entrainment to embedded words increased logarithmically over the learning period, consistent with a perceptual shift from isolated syllables to wordlike units. Moreover, infants’ neural entrainment during learning predicted postlearning behavioral measures of word discrimination ( n = 18). Finally, the logarithmic increase in entrainment to words was comparable in infants and adults, suggesting that infants and adults follow similar learning trajectories when tracking probability information among speech sounds. Statistical-learning effects in infants and adults may reflect overlapping neural mechanisms, which emerge early in life and are maintained throughout the life span.

Will people use self-driving cars, virtual doctors, and other algorithmic decision-makers if they outperform humans? The answer depends on the uncertainty inherent in the decision domain. We propose that people have diminishing sensitivity to forecasting error and that this preference results in people favoring riskier (and often worse-performing) decision-making methods, such as human judgment, in inherently uncertain domains. In nine studies ( N = 4,820), we found that (a) people have diminishing sensitivity to each marginal unit of error that a forecast produces, (b) people are less likely to use the best possible algorithm in decision domains that are more unpredictable, (c) people choose between decision-making methods on the basis of the perceived likelihood of those methods producing a near-perfect answer, and (d) people prefer methods that exhibit higher variance in performance (all else being equal). To the extent that investing, medical decision-making, and other domains are inherently uncertain, people may be unwilling to use even the best possible algorithm in those domains.

It has been proposed that somatosensory reaction to varied social circumstances results in feelings (i.e., conscious emotional experiences). Here, we present two preregistered studies in which we examined the topographical maps of somatosensory reactions associated with violations of different moral concerns. Specifically, participants in Study 1 ( N = 596) were randomly assigned to respond to scenarios involving various moral violations and were asked to draw key aspects of their subjective somatosensory experience on two 48,954-pixel silhouettes. Our results show that body patterns corresponding to different moral violations are felt in different regions of the body depending on whether individuals are classified as liberals or conservatives. We also investigated how individual differences in moral concerns relate to body maps of moral violations. Finally, we used natural-language processing to predict activation in body parts on the basis of the semantic representation of textual stimuli. We replicated these findings in a nationally representative sample in Study 2 ( N = 300). Overall, our findings shed light on the complex relationships between moral processes and somatosensory experiences.

Many of us “see red,” “feel blue,” or “turn green with envy.” Are such color-emotion associations fundamental to our shared cognitive architecture, or are they cultural creations learned through our languages and traditions? To answer these questions, we tested emotional associations of colors in 4,598 participants from 30 nations speaking 22 native languages. Participants associated 20 emotion concepts with 12 color terms. Pattern-similarity analyses revealed universal color-emotion associations (average similarity coefficient r = .88). However, local differences were also apparent. A machine-learning algorithm revealed that nation predicted color-emotion associations above and beyond those observed universally. Similarity was greater when nations were linguistically or geographically close. This study highlights robust universal color-emotion associations, further modulated by linguistic and geographic factors. These results pose further theoretical and empirical questions about the affective properties of color and may inform practice in applied domains, such as well-being and design.

Happier people are healthier, but does becoming happier lead to better health? In the current study, we deployed a comprehensive, 3-month positive psychological intervention as an experimental tool to examine the effects of increasing subjective well-being on physical health in a nonclinical population. In a 6-month randomized controlled trial with 155 community adults, we found effects of treatment on self-reported physical health—the number of days in the previous month that participants felt healthy or sick, as assessed by questions from the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System Questionnaire. In a subsample of 100 participants, we also found evidence that improvements in subjective well-being over the course of the program predicted subsequent decreases in the number of sick days. Combining experimental and longitudinal methodologies, this work provides some evidence for a causal effect of subjective well-being on self-reported physical health.

In this article, we present a tool and a method for measuring the psychological and cultural distance between societies and creating a distance scale with any population as the point of comparison. Because psychological data are dominated by samples drawn from Western, educated, industrialized, rich, and democratic (WEIRD) nations, and overwhelmingly, the United States, we focused on distance from the United States. We also present distance from China, the country with the largest population and second largest economy, which is a common cultural comparison. We applied the fixation index ( F ST ), a meaningful statistic in evolutionary theory, to the World Values Survey of cultural beliefs and behaviors. As the extreme WEIRDness of the literature begins to dissolve, our tool will become more useful for designing, planning, and justifying a wide range of comparative psychological projects. Our code and accompanying online application allow for comparisons between any two countries. Analyses of regional diversity reveal the relative homogeneity of the United States. Cultural distance predicts various psychological outcomes.

Whether acquiring a second language affords any general advantages to executive function has been a matter of fierce scientific debate for decades. If being bilingual does have benefits over and above the broader social, employment, and lifestyle gains that are available to speakers of a second language, then it should manifest as a cognitive advantage in the general population of bilinguals. We assessed 11,041 participants on a broad battery of 12 executive tasks whose functional and neural properties have been well described. Bilinguals showed an advantage over monolinguals on only one test (whereas monolinguals performed better on four tests), and these effects all disappeared when the groups were matched to remove potentially confounding factors. In any case, the size of the positive bilingual effect in the unmatched groups was so small that it would likely have a negligible impact on the cognitive performance of any individual.

Stressful events are often vividly remembered. Although generally adaptive to survival, this emotional-memory enhancement may contribute to stress-related disorders. We tested here whether the enhanced memory for stressful events is due to the expectancy violation evoked by these events. Ninety-four men and women underwent a stressful or control episode. Critically, to manipulate the degree of expectancy violation, we gave participants either detailed or minimal information about the stressor. Although the subjective and hormonal stress responses were comparable in informed and uninformed participants, prior information about the stressor abolished the memory advantage for core features of the stressful event, tested 7 days later. Using functional near-infrared spectroscopy, we further linked the expectancy violation and memory formation under stress to the inferior temporal cortex. These data are the first to show that detailed information about an upcoming stressor and, by implication, a reduced expectancy violation attenuates the memory for stressful events.

Religion shapes the nature of intergroup conflict, but conflict may also shape religion. Here, we report four multimethod studies that reveal the impact of conflict on religious belief: The threat of warfare and intergroup tensions increase the psychological need for order and obedience to rules, which leads people to view God as more punitive. Studies 1 ( N = 372) and 2 ( N = 911) showed that people’s concern about conflict correlates with belief in a punitive God. Study 3 ( N = 1,065) found that experimentally increasing the salience of conflict increases people’s perceptions of the importance of a punitive God, and this effect is mediated by people’s support for a tightly regulated society. Study 4 showed that the severity of warfare predicted and preceded worldwide fluctuations in punitive-God belief between 1800 CE and 2000 CE. Our findings illustrate how conflict can change the nature of religious belief and add to a growing literature showing how cultural ecologies shape psychology.

Across two studies with more than 1,700 U.S. adults recruited online, we present evidence that people share false claims about COVID-19 partly because they simply fail to think sufficiently about whether or not the content is accurate when deciding what to share. In Study 1, participants were far worse at discerning between true and false content when deciding what they would share on social media relative to when they were asked directly about accuracy. Furthermore, greater cognitive reflection and science knowledge were associated with stronger discernment. In Study 2, we found that a simple accuracy reminder at the beginning of the study (i.e., judging the accuracy of a non-COVID-19-related headline) nearly tripled the level of truth discernment in participants’ subsequent sharing intentions. Our results, which mirror those found previously for political fake news, suggest that nudging people to think about accuracy is a simple way to improve choices about what to share on social media.