People frequently engage in dishonest behavior at a cost to others, and it is therefore beneficial to study interventions promoting honest behavior. We implemented a novel intervention that gave participants a choice to promise to be truthful or not to promise. To measure cheating behavior, we developed a novel variant of the mind game—the dice‐box game—as well as a child‐friendly sender–receiver game. Across three studies with adolescents aged 10 to 14 years (N = 640) from schools in India, we found that promises systematically lowered cheating rates compared with no‐promise control conditions. Adolescents who sent truthful messages in the sender–receiver game cheated less in the dice‐box game and promises reduced cheating in both tasks (Study 1). Promises in the dice‐box game remained effective when negative externalities (Study 2) or incentives for competition (Study 3) were added. A joint analysis of data from all three studies revealed demographic variables that influenced cheating. Our findings confirm that promises have a strong, binding effect on behavior and can be an effective intervention to reduce cheating.

BackgroundDeveloping countries, such as India, are experiencing rapid urbanization, which may have a major impact on the environment: including worsening air and water quality, noise and the problems of waste disposal. We used health data from an ongoing cohort study based in southern India to examine the relationship between the urban environment and homeostasis model assessment of insulin resistance (HOMA-IR).MethodsWe utilized three metrics of urbanization: distance from urban center; population density in the India Census; and satellite-based land cover. Restricted to participants without diabetes (N = 6350); we built logistic regression models adjusted for traditional risk factors to test the association between urban environment and HOMA-IR.ResultsIn adjusted models, residing within 0–20 km of the urban center was associated with an odds ratio for HOMA-IR of 1.79 (95% CI 1.39, 2.29) for females and 2.30 (95% CI 1.64, 3.22) for males compared to residing in the furthest 61–80 km distance group. Similar statistically significant results were identified using the other metrics.ConclusionsWe identified associations between urban environment and HOMA-IR in a cohort of adults. These associations were robust using various metrics of urbanization and adjustment for individual predictors. Our results are of public health concern due to the global movement of large numbers of people from rural to urban areas and the already large burden of diabetes.Electronic supplementary materialThe online version of this article (10.1186/s12942-019-0169-9) contains supplementary material, which is available to authorized users.

Urbanization is associated with higher prevalence of cardiovascular disease worldwide. Aortic stiffness, as measured by carotid-femoral pulse wave velocity is a validated predictor of cardiovascular disease. Our objective was to determine the association between urbanization and carotid-femoral pulse wave velocity. The analysis included 6166 participants enrolled in an ongoing population-based study (mean age 42 years; 58% female) who live in an 80 × 80 km region of southern India. Multiple measures of urbanization were used and compared: 1) census designations, 2) satellite derived land cover (crops, grass, shrubs or trees as rural; built-up areas as urban), and 3) distance categories based on proximity to an urban center. The association between urbanization and carotid-femoral pulse wave velocity was tested in sex-stratified linear regression models. People residing in urban areas had significantly (p < 0.05) elevated mean carotid-femoral pulse wave velocity compared to non-urban populations after adjustment for other risk factors. There was also an inverse association between distance from the urban center and mean carotid-femoral pulse wave velocity: each 10 km increase in distance was associated with a decrease in mean carotid-femoral pulse wave velocity of 0.07 m/s (95% CI: -0.09, -0.06 m/s). The association was stronger among older participants, among smokers, and among those with other cardiovascular risk factors. Further research is needed to determine which components in the urban environment are associated with higher carotid-femoral pulse wave velocity.

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Background: Rapid urbanization is driving economies of South Asian countries. Here we use satellite based land cover data and distance to urban center (UC) to measure of the impact of urban environment on arterial stiffness (AS) in a population based study in South India. Methods: In a cross-sectional analysis, after exclusion of people with previous history of diabetes and hypertension, 6746 subjects (mean age 42 years; 54% women) spread over 78 kms from the UC constituted the study sample. MODIS satellite derived land cover data at a 1 km x 1 km resolution was obtained and joined to each participant's geolocated residential position in ArcGIS to assign urban and rural designations. The study included carotid-femoral pulse wave velocity (PWV) measurement using a high-fidelity applanation tonometry, blood pressure (BP), anthropometric, psychosocial, high sensitive C-reactive protein (HsCRP) and other biomarkers assessments. Results: Based on land cover analysis, participants in urban locations had a mean (SD) PWV (m/s) of 7.74 (1.65) compared to 7.6 (1.62) in rural locations (p= 0.002) [Fig 1], while there was no significant difference in HsCRP levels. In multiple regression analyses adjusting for age, smoking, BMI, BP, blood glucose, LDL, socioeconomic, anxiety and stress levels, distance from UC was independently associated with PWV in men (β = -0.007, p <0.001), but not in women. Standardized effect-estimates in the multi-linear regression model indicated that distance from UC had the third largest effect on PWV after age and BP. After multivariable adjustments, the largest effect of distance from UC on PWV was on non-smoking men age 46-75 years. Residing every 1 km further away from the UC corresponded with a -0.012 m/s (95%CI: -0.020, -0.003) decrease in PWV. Conclusions: Urbanization is an independent predictor of AS in men, more so in non-smoking older men. Further research will elucidate components in the urban environment that may be contributing to higher AS.