Inconsistent with the data: Support for the CLASH model depends on the wrong kind of latitude (original) (raw)
The CLASH model lacks evolutionary and archeological support
Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model, CLimate, Aggression, and Self-control in Humans (CLASH), that helps us to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, a greater focus on the future (vs. present), and a stronger focus on self-control. The CLASH model further outlines that slow life strategy, future orientation, and strong self-control are important determinants of inhibiting aggression and violence. We also discuss how CLASH differs from other recently developed models that emphasize climate differences for understanding conflict. We conclude by discussing the theoretical and societal importance of climate in shaping individual and societal differences in aggression and violence.
Hsiang, Influence of climate on Human conflict (2013)
A rapidly growing body of research examines whether human conflict can be affected by climatic changes. Drawing from archeology, criminology, economics, geography, history, political science, and psychology, we assemble and analyze the 60 most rigorous quantitative studies and document, for the first time, a remarkable convergence of results. We find strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world. The magnitude of climate's influence is substantial: for each 1 standard deviation (1σ) change in climate toward warmer temperatures or more extreme rainfall, median estimates indicate that the frequency of interpersonal violence rises 4% and the frequency of intergroup conflict rises 14%. Because locations throughout the inhabited world are expected to warm 2-4σ by 2050, amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.
CLASH: Climate (change) and cultural evolution of intergroup conflict
Group Processes & Intergroup Relations
Aggression and violence levels generally increase as one moves closer to the equator, but why? We developed a new theoretical model, CLimate, Aggression, and Self-control in Humans (CLASH; van Lange, Rinderu, & Bushman, 2017b, 2017c), to understand differences within and between countries in aggression and violence in terms of differences in climate. Colder temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, revealed in a greater focus on the future (vs. present) and a stronger focus on self-control—variables that are known to inhibit aggression and violence. Other variables (e.g., wealth, income inequality, parasite stress) are also linked to both climate differences and to aggression and violence differences. When people think of the consequences of climate change, they rarely think of the impact on aggression and violence levels, but they should. CLASH has broad implications for the...
Climate, aggression, and violence (CLASH): a cultural-evolutionary approach
Current Opinion in Psychology
The CLimate, Aggression, and Self-control in Humans (CLASH) proposes that aggression and violence increase as climates become hotter and seasonal variation becomes smaller by influencing time-orientation and self-control. Emerging empirical evidence supporting the model is reviewed. Wealth, income inequality, and pathogen stress as powerful influences of these processes are also discussed. We conclude by discussing the theoretical and societal importance of climate change in shaping violence.
Climate, conflict, and social stability: what does the evidence say?
Climatic Change, 2013
Are violent conflict and socio-political stability associated with changes in climatological variables? We examine 50 rigorous quantitative studies on this question and find consistent support for a causal association between climatological changes and various conflict outcomes, at spatial scales ranging from individual buildings to the entire globe and at temporal scales ranging from an anomalous hour to an anomalous millennium. Multiple mechanisms that could explain this association have been proposed and are sometimes supported by findings, but the literature is currently unable to decisively exclude any proposed pathway. Several mechanisms likely contribute to the outcomes that we observe.
One effect to rule them all? A comment on climate and conflict
A recent Climatic Change review article reports a remarkable convergence of scientific evidence for a link between climatic events and violent intergroup conflict, thus departing markedly from other contemporary assessments of the empirical literature. This commentary revisits the review in order to understand the discrepancy. We believe the origins of the disagreement can be traced back to the review article's underlying quantitative meta-analysis,
Climate change and violent conflict in Europe over the last millennium
Climatic Change, 2010
We investigate the relationship between a thousand-year history of violent conflict in Europe and various reconstructions of temperature and precipitation. We find that conflict was more intense during colder periods. This relationship is weakening over time, and is not robust to the details of the climate reconstruction or to the sample period. We thus confirm Zhang et al. (2006, Climatic Change, 76, 459-477) that, at least in temperate climates, global warming would, if anything, lead to reduced violent conflict.
The Long-Term Patterns of Violent Conflict in Different Regions of the World
This paper is an interim report of a long-term project to develop a taxonomy of violent conflicts and ultimately a conflict early warning system. The paper first describes the nature of the conflict early warning problem---as the author perceives it---that shapes the design decisions the author has made. The paper then describes the Conflict Catalog, a listing of all recorded violent conflicts that meet Richardson's magnitude 1.5 or higher criterion (32 or more deaths). The Conflict Catalog is a dataset designed for the purpose of making a conflict taxonomy that is comprehensive in terms of the types of conflicts included and extensive in terms of encompassing conflicts in all regions of the world since 1400 AD. The paper presents "in-progress" findings from the catalog for the regions of the world for which a reasonably complete compilation has been assembled. The paper then describes a list of variables that define the criteria for placing historical conflicts into t...
PsycEXTRA Dataset
The FGGD climate constraints map is a global raster datalayer with a resolution of 5 arcminutes. Each pixel contains a class value for the degree to which climate constrains agricultural production potential in the pixel area. The data are from FAO and IIASA, 2000, Global agro-ecological zones, as reported in FAO and IIASA, 2007, Mapping biophysical factors that influence agricultural production and rural vulnerability, by H. von Velthuizen et al. Purpose The FGGD Digital Atlas consists of more than 100 global database that allows to analyse food insecurity and poverty in relation to the environment. Status completed Point of contact Organisation name FAO
The Behavioral and brain sciences, 2016
Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model of CLimate, Aggression, and Self-control in Humans (CLASH) that seeks to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degr...
Climate as a Cause of Conflict: An Econometric Analysis
2016
In recent decades, there has been assertions that climate change triggers conflict via multiple pathways, including food shortages, pest and disease incidence expansion, and water scarcity. However, broad empirical studies on the link are still lacking. This study aims to quantitatively explore that linkage using a global dataset. This involves development of a model that predicts the probability of conflict incidence given climate variations. We apply both parametric and semiparametric techniques in a rolling window scheme, which allows for a system that evolves over time. Two criteria are employed to evaluate out-of-sample predictive capability of the estimated models. Our investigation suggests that precipitation variation has a statistically significant effect on conflict. Generally we find the more that this year’s precipitation is smaller than last years the more likely is civil conflict.
Unseasonably Violent? Climate Pressure, Horizontal Inequalities, and One-Sided Violence
Is government-directed violence against civilians more likely to occur during or following periods of climatic instability, and if so, what can be said about causal mechanisms underlying this relationship? Increasing climatic instability is expected to be a consequence of global climate change, motivating much scholarship examining relationships between extreme weather variation and security issues. However, very little existing work considered government-directed one-sided violence. Case study literature suggests several possible mechanisms through which climatic instability may make violence against civilians more likely, but the degree to which these are generalizable has not been examined empirically. Here, I attempt to empirically test the overall relationship between climatic instability and violence against civilians, as well as several possible causal mechanisms. I utilize a geographically-specific design allowing substantial precision in identifying climatic variation in relation to incidences of violence, and find support for a connection between climatic instability and violence against civilians. Findings suggest a relationship where increasing climate pressure may drive repressive violence in areas where unrest is likely to be more costly or strategically-threatening to governments.
Climate change and violent conflict in Europe over the last millenniuam
We investigate the relationship between a thousand-year history of violent conflict in Europe and various reconstructions of temperature and precipitation. We find that conflict was more intense during colder period, just like Zhang et al. (Clim Change 76:459–477, 2006) found for China. This relationship weakens in the industrialized era, and is not robust to the details of the climate reconstruction or to the sample period. As the correlation is negative and weakening, it appears that global warming would not lead to an increase in violent conflict in temperature climates.
Temperature extremes, global warming, and armed conflict: new insights from high resolution data
World Development, 2019
This paper contributes to the debate whether climate change and global warming cause conflicts by providing novel evidence about the role of extreme temperature events for armed conflict based on highfrequency high-resolution data for the entire continent of Africa. The analysis of monthly data for 4826 grid cells of 0.75°latitude  longitude over the period 1997-2015 documents a positive effect of the occurrence of temperature extremes on conflict incidence. These effects are larger the more severe the extremes in terms of duration, and are larger in highly densely populated regions, in regions with lower agricultural productivity, and in regions with more pronounced land degradation. The results also point towards heterogeneity of the effect with respect to the type of violence and the crucial role of population dynamics. Considering the consequences of increases in the frequency of extreme events in a long-differences analysis delivers evidence for a positive effect on conflict.
Climatic Conditions and Internal Armed Conflict : An Empirical Study
2018
While climatic conditions are believed to have some influence on triggering conflicts, the existing empirical results on the nature and statistical significance of their explanatory role are not conclusive. We construct a dataset for a sample of 139 countries which records the occurrence of an armed conflict, the annual average temperature and precipitation levels as well as the relevant socio-economic, demographic and geographic measures over the 19612011 period. Using this dataset and controlling for the effect of relevant non-climate variables, our regression analyses support the significant explanatory role of climatic factors. Our results are consistent with the hypothesis that climate warming is instrumental in raising the probability of onset of internal armed conflicts and suggest that, along with regulating population size and promoting political stability, controlling climate change is one of the most effective factors for inducing peace by way of curtailing the onset of a...
Temper and temperature: the missing link of climate on armed conflicts
RePEc: Research Papers in Economics, 2014
We investigate the causes of a conflict by adding ambient climate factors to the existing bundle of most significant variables. It turns out thatcontrolling for possible associations temperature could actually induce a conflict. We emphasise that temperature could not be a dominant reason in starting a conflict; however, it could escalate the chances when other factors are present. This paper references some of the related psychological studies to support this claim. We also show that grievance factors could actually be rightfully effective in starting an internal conflict alongside greed based reasons. In the end, we believe that it could be informative to study ambient factors more often in economics.
The Decline of Violent Conflicts: What Do The Data Really Say
We propose a methodology to look at violence in particular, and other aspects of quantitative historiography in general in a way compatible with statistical inference, which needs to accommodate the fat-tailedness of the data and the unreliability of the reports of conflicts. We investigate the theses of " long peace " and drop in violence and find that these are statistically invalid and resulting from flawed and naive methodologies, incompatible with fat tails and non-robust to minor changes in data formatting and methodologies. There is no statistical basis to claim that " times are different " owing to the long inter-arrival times between conflicts; there is no basis to discuss any " trend " , and no scientific basis for narratives about change in risk. We describe naive empiricism under fat tails. We also establish that violence has a " true mean " that is underestimated in the track record. This is a historiographical adaptation of the results in Cirillo and Taleb (2016). PUBLISHED IN "PROCEEDINGS OF THE NOBEL SYMPOSIUM", NOBEL COMMISSION.