This essay has two goals. The first is to show that the heat hypothesis, per se, provides a partial explanation of causes of the violent crime in society. The second is to stress the importance of the concept of socioeconomic inequality that can negatively affect mental health and induce violence, controlling the climate factor. In fact, a fundamental problem in social psychology is what environmental stressors lead to aggressive behavior and violent crime in society. The vast literature has suggested several approaches, such as the heat hypothesis that more violence is associated to very hot temperature. However, the manifold determinants of violent crime in society are hardly known. This study shows that, controlling the climate, the socioeconomic inequality at country level negatively affects human functioning and leads to high rates of violent crime in society. In particular, the statistical evidence seems in general to support the hypothesis that, controlling the climate, the intentional homicides (per 100,000 people) can be explained by the high level of income inequality, both in hot tropical areas and in temperate zone of the globe. The socioeconomic inequality is one of contributing factors that generates aversive environments and, as a consequence, a deteriorated human behavior leading to high rates of intentional homicides in society. The interdisciplinary results here, combining psychological and sociological approaches, suggest an alternative hypothesis that can integrate the current theoretical frameworks to explain one of principal causes of deteriorated human functioning that leads to violent crime in society. Overall, then, these findings can clarify whenever possible, a vital source of the aggressive behavior and violent crime, controlling the climate, to support appropriate policies directed to preempt these critical problems in society.