Killing the Competition: Economic Inequality and Homicide

Daly argues that economic inequality is a cause of high homicide rates because lethal violence represents the extreme end of male-male competition. Criminologists have long known that income inequality predicts local homicide rates, but the mechanism has remained unexplained. Daly's answer: most homicides are the outcomes of competitive interactions between men. Where desired goods are distributed inequitably and competition for those goods is severe, dangerous competitive tactics become appealing, and elevated homicide rates are one consequence. The book applies basic principles of behavioral biology to explain why killers are usually men rather than women, and it counters the view that attitudes and values in cultures of violence make change impossible .

Daly identifies and systematically dispels three common defenses of inequality. First, the claim that absolute poverty is the real problem and inequality is merely an incidental correlate. Second, the assertion that primitive egalitarian societies have surprisingly high homicide rates, undermining the inequality-violence link. Third, the argument that inequality and homicide rates do not change in synchrony and are therefore mutually irrelevant. Using detailed but accessible data analyses and thorough reviews of relevant research, Daly demonstrates that none of these defenses withstand scrutiny. He maintains that economic inequality is not merely correlated with violence but causally implicated in producing it, and that acknowledging this elicits fierce opposition from inequality's beneficiaries .

Daly applies principles of behavioral biology to explain the stark sex difference in homicide. In every country with a non-negligible homicide rate, men kill men far more often than they kill women—by a worldwide factor of nearly four to one. Daly argues that this pattern reflects the fierce competition that nearly all male mammals exhibit, primarily for mates and the resources that attract them. Male reproductive success is typically more variable than female reproductive success, and intrasexual competition has shaped male psychology toward greater risk-taking and willingness to use dangerous tactics when status and resources are at stake. This is not a justification but an explanation: lethal violence emerges from the same competitive logic that drives male striving .

Killing the Competition extends the research program Daly and Margo Wilson developed over decades, most notably in Homicide (1988) and their 1990 paper on female/female and male/male homicide. Where the earlier works established that homicide follows predictable patterns rooted in evolved psychology—sexual jealousy, parental investment, status competition—Killing the Competition focuses specifically on the economic dimension of that framework. Daly had already published on the relationship between income inequality and homicide in Canada and the United States with Wilson and Vasdev (2001). This book represents the culmination of that line of inquiry, offering a comprehensive evolutionary explanation for why economic inequality, rather than poverty alone, drives lethal violence .

Daly draws on cross-national and cross-cultural data showing that income inequality consistently predicts homicide rates better than absolute poverty. He reviews research demonstrating that the relationship holds across developed nations, within cities and neighborhoods, and over time. The book counters the culture of violence thesis by arguing that attitudes and values do not make change impossible; rather, the competitive dynamics created by severe inequality produce violence regardless of cultural context. Daly also addresses the claim that egalitarian societies have high homicide rates, showing that such assertions rely on questionable data or definitions. The New Scientist praised the book as a thought-provoking and important work that meticulously builds the case for inequality's causal role .