Abstract
BACKGROUND: We can see outbreaks of social violence (notably wars, riots, and revolutions), both historically and in the current social situation. Some authors point to the impact of hostility on human cognitive processes and on decision making, and through these factors - on aggressive behaviour. Moreover, some retrospective studies note the role of cognitive complexity in the peaceful resolution of conflicts (including international conflicts). These findings prompted us to ask whether the two phenomena are related. To answer this question a meta-analysis of correlation between hostility and cognitive complexity was conducted. OBJECTIVE: Our objective was to summarise research findings on the relationship between hostility and cognitive complexity. DESIGN: The total number of papers screened was 839 (in English and Russian). A total of 5 effect sizes from 4 selected papers were included in the meta-analysis derived from a pooled sample of 3114 participants. Three-level random-effects meta-analysis, p-curve, p-uniform and p-uniform* methods were used in the data analysis. RESULTS: The results of different effect size calculation methods (three-level random-effects model, two-level random-effects model, and p-uniform*) confirmed that there is a moderately weak negative correlation between hostility and cognitive complexity. The most accurate result is r(pooled) = -.22 [-.45; .003]. CONCLUSION: There is a negative correlational relationship between hostility and cognitive complexity. Apparently, hostility and cognitive complexity have some reciprocal influence on each other. The authors hypothesise that hostility is rather complementary to cognitive simplicity as the opposite pole of cognitive complexity - if the function of hostility in ensuring the protection of one's sense of Self is taken into account. Both hostility and cognitive simplicity work to create a simple (in one case dangerous, in another case unambiguous) world in which it is easier to make decisions (including the decision to engage in aggressive behaviour).