Better explicating the strengths and shortcomings of these models will help refine projections and improve transparency in the years ahead.
Image credit: Witsawat.S.
Edited by Susan T. Fiske, Princeton University, Princeton, NJ, and approved June 26, 2017 (received for review March 21, 2017)
Article Figures & SI
Figures
- Fig. 1.
Impact of ETV on short-term memory. Accuracy levels in the memory task are broken down by recall condition (VR vs. NR) and levels of ETV—high or low ETV. High ETV identifies subjects lying above the distribution’s 75th-percentile split of the district-level homicide rate in the urban sample (A) and of a self-reported ETV measure for the war-displaced sample (B). Error bars reflect ±95% confidence intervals. Top horizontal bars show the statistical significance of tests on the null hypothesis that accuracy is the same in pairs of groups, as per Tobit regression reported in SI Appendix, Table S8 (A) and SI Appendix, Table S14 (B). †P < 0.1; *P < 0.05; **P < 0.01; ***P < 0.001.
- Fig. 2.
Impact of ETV on cognitive control. Accuracy levels in the Stroop task and Raven sequential matrices task are broken down by recall condition (VR vs. NR) and levels of ETV—high or low ETV. High ETV identifies subjects lying above the 75th-percentile split of the distribution of the self-reported ETV measure. Error bars reflect ±95% confidence intervals. Top horizontal bars show the statistical significance of tests on the null hypothesis that accuracy is the same in pairs of groups, as per Tobit regression reported in SI Appendix, Table S16 (A) and SI Appendix, Table S18 (B). †P < 0.1; *P < 0.05; **P < 0.01.
- Fig. 3.
Intersubject variability of cognitive control measurements (experiments I and II). The scatterplot of ETV (measured on a continuous scale) and accuracy on the three cognitive tests is reported. Linear predictions for experiment I (urban sample) and experiment II (rural environment, war-displaced sample) are also plotted, and their slopes are reported. A and B report observations in the VR and NR groups, respectively.
Tables
- Table 1.
Analysis of effects of ETV and VR on short-term memory and cognitive control: experiments I and II
Variables Urban War-displaced All Memory Memory Stroop Raven ETV (VR group) −7.25* (3.23) −33.10*** (7.41) −13.34† (7.90) −8.80 (10.10) −12.43** (3.91) ETV (NR group) −0.28 (2.52) 7.93 (11.04) 5.89 (4.65) 10.29 (9.13) 1.87 (2.29) ETV (VR group) – ETV (NR group) −6.97† (4.01) −41.03** (11.02) −19.23* (9.50) −19.09 (14.32) −14.31** (4.51) VR (HV group) −6.05† (3.38) −40.10** (11.07) 18.45* (7.82) −13.36 (11.85) −13.96*** (3.95) Observations 281 30 141 67 516 VR (overall) −1.09 (1.89) −3.94 (8.24) −10.05* (3.97) 1.72 (4.57) −3.29† (1.83) Observations 281 30 141 88 540 ETV (overall) −2.56 (2.07) −4.63 (10.45) −4.36 (4.89) 0.59 (6.54) 3.68† (2.17) Observations 281 30 141 67 516 The table reports results from econometric analysis to explain the degree of accuracy on short-term memory (with respect to the urban and war-displaced samples), inhibitory control (Stroop task), and fluid intelligence (Raven task). The last column pools the three tasks and the two samples together. Various Tobit models have been fitted, which also include demographic and treatment controls (see SI Appendix, Tables S8, S9, and S14–S21 for full results). The estimated effect on accuracy of ETV is reported for both VR and NR groups, as well as the difference of its effect in the two groups (difference-in-difference). The estimated effect of VR within the HV group only is also reported. Finally, the estimated overall effects of VR and ETV are reported. Robust SEs (clustered at the individual level for regression in the last column) are reported in parentheses. †P < 0.1; *P < 0.05; **P < 0.01; ***P < 0.001.
Data supplements
Violence reduces memory and cognitive control
Article Classifications
- Social Sciences
- Psychological and Cognitive Sciences
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