Knowledge that Transforms

Air pollution is a serious problem that affects billions of people globally. Although the environmental and health costs of air pollution are well known, the present research investigates its ethical costs. We propose that air pollution can increase criminal and unethical behavior by increasing anxiety. Analyses of a 9-year panel of 9,360 U.S. cities found that air pollution predicted six major categories of crime; these analyses accounted for a comprehensive set of control variables (e.g., city and year fixed effects, population, law enforcement) and survived various robustness checks (e.g., balanced panel, nonparametric bootstrapped standard errors). Three subsequent experiments involving American and Indian participants established the causal effect of psychologically experiencing a polluted (vs. clean) environment on unethical behavior. Consistent with our theoretical perspective, results revealed that anxiety mediated this effect. Air pollution not only corrupts people’s health, but also can contaminate their morality.

The way we respond to life’s daily stressors has strong implications for our physical health. Researchers have documented the detrimental effects of initial emotional reactivity to daily stressors on future physical health outcomes but have yet to examine the effects of emotions that linger after a stressor occurs. The current study investigated how negative affect that lingers the day after a minor stressor occurs is associated with health-related outcomes. Participants ( N = 1,155) in a community-based, nationwide study answered questions about daily stressors and affect across 8 consecutive days and about their physical health almost 10 years later. Multilevel models indicated that people experience heightened levels of negative affect the day after a stressor occurs. Furthermore, higher levels of lingering negative affect are associated with greater numbers of chronic conditions and worse functional limitations 10 years later. Findings suggest that affective recovery from daily stressors has unique importance for long-term physical health.

Intelligence test scores and educational duration are positively correlated. This correlation could be interpreted in two ways: Students with greater propensity for intelligence go on to complete more education, or a longer education increases intelligence. We meta-analyzed three categories of quasiexperimental studies of educational effects on intelligence: those estimating education-intelligence associations after controlling for earlier intelligence, those using compulsory schooling policy changes as instrumental variables, and those using regression-discontinuity designs on school-entry age cutoffs. Across 142 effect sizes from 42 data sets involving over 600,000 participants, we found consistent evidence for beneficial effects of education on cognitive abilities of approximately 1 to 5 IQ points for an additional year of education. Moderator analyses indicated that the effects persisted across the life span and were present on all broad categories of cognitive ability studied. Education appears to be the most consistent, robust, and durable method yet to be identified for raising intelligence.

The underrepresentation of girls and women in science, technology, engineering, and mathematics (STEM) fields is a continual concern for social scientists and policymakers. Using an international database on adolescent achievement in science, mathematics, and reading ( N = 472,242), we showed that girls performed similarly to or better than boys in science in two of every three countries, and in nearly all countries, more girls appeared capable of college-level STEM study than had enrolled. Paradoxically, the sex differences in the magnitude of relative academic strengths and pursuit of STEM degrees rose with increases in national gender equality. The gap between boys’ science achievement and girls’ reading achievement relative to their mean academic performance was near universal. These sex differences in academic strengths and attitudes toward science correlated with the STEM graduation gap. A mediation analysis suggested that life-quality pressures in less gender-equal countries promote girls’ and women’s engagement with STEM subjects.

Déjà vu is beginning to be scientifically understood as a memory phenomenon. Despite recent scientific advances, a remaining puzzle is the purported association between déjà vu and feelings of premonition. Building on research showing that déjà vu can be driven by an unrecalled memory of a past experience that relates to the current situation, we sought evidence of memory-based predictive ability during déjà vu states. Déjà vu did not lead to above-chance ability to predict the next turn in a navigational path resembling a previously experienced but unrecalled path (although such resemblance increased reports of déjà vu). However, déjà vu states were accompanied by increased feelings of knowing the direction of the next turn. The results suggest that feelings of premonition during déjà vu occur and can be illusory. Metacognitive bias brought on by the state itself may explain the peculiar association between déjà vu and the feeling of premonition.

The tendency for the mind to wander to concerns other than the task at hand is a fundamental feature of human cognition, yet the consequences of variations in its experiential content for psychological functioning are not well understood. Here, we adopted multivariate pattern analysis to simultaneously decompose experience-sampling data and neural functional-connectivity data, which revealed dimensions that simultaneously describe individual variation in self-reported experience and default-mode-network connectivity. We identified dimensions corresponding to traits of positive-habitual thoughts and spontaneous task-unrelated thoughts. These dimensions were uniquely related to aspects of cognition, such as executive control and the ability to generate information in a creative fashion, and independently distinguished well-being measures. These data provide the most convincing evidence to date for an ontological view of the mind-wandering state as encompassing a broad range of different experiences and show that this heterogeneity underlies mind wandering’s complex relationship to psychological functioning.

We report a novel transposed-word effect in speeded grammaticality judgments made about five-word sequences. The critical ungrammatical test sequences were formed by transposing two adjacent words from either a grammatical base sequence (e.g., “The white cat was big” became “The white was cat big”) or an ungrammatical base sequence (e.g., “The white cat was slowly” became “The white was cat slowly”). These were intermixed with an equal number of correct sentences for the purpose of the grammaticality judgment task. In a laboratory experiment ( N = 57) and an online experiment ( N = 94), we found that ungrammatical decisions were harder to make when the ungrammatical sequence originated from a grammatically correct base sequence. This provides the first demonstration that the encoding of word order retains a certain amount of uncertainty. We further argue that the novel transposed-word effect reflects parallel processing of words during written sentence comprehension combined with top-down constraints from sentence-level structures.