A Test of Evolutionary Policing Theory with Data from Human Societies

In social groups where relatedness among interacting individuals is low, cooperation can often only be maintained through mechanisms that repress competition among group members. Repression-of-competition mechanisms, such as policing and punishment, seem to be of particular importance in human societies, where cooperative interactions often occur among unrelated individuals. In line with this view, economic games have shown that the ability to punish defectors enforces cooperation among humans. Here, I examine a real-world example of a repression-of-competition system, the police institutions common to modern human societies. Specifically, I test evolutionary policing theory by comparing data on policing effort, per capita crime rate, and similarity (used as a proxy for genetic relatedness) among citizens across the 26 cantons of Switzerland. This comparison revealed full support for all three predictions of evolutionary policing theory. First, when controlling for policing efforts, crime rate correlated negatively with the similarity among citizens. This is in line with the prediction that high similarity results in higher levels of cooperative self-restraint (i.e. lower crime rates) because it aligns the interests of individuals. Second, policing effort correlated negatively with the similarity among citizens, supporting the prediction that more policing is required to enforce cooperation in low-similarity societies, where individuals' interests diverge most. Third, increased policing efforts were associated with reductions in crime rates, indicating that policing indeed enforces cooperation. These analyses strongly indicate that humans respond to cues of their social environment and adjust cheating and policing behaviour as predicted by evolutionary policing theory

Female homicidal strangulation in urban South Africa

<p>Abstract</p> <p>Background</p> <p>Female strangulation in South Africa occurs in a context of pervasive and often extreme violence perpetrated against women, and therefore represents a major public health, social and human rights concern. South African studies that provide accurate descriptions of the occurrence of strangulation incidents among female homicide victims are limited. The current study describes the extent, distribution and patterns of homicidal strangulation of women in the four largest South African metropolitan centres, Tshwane/Pretoria, Johannesburg, Cape Town and Ethekwini/Durban.</p> <p>Methods</p> <p>The study is a register-based cross sectional investigation of female homicidal strangulation, as reported in the National Injury Mortality Surveillance System for the four cities, for the period 2001 to 2005. Crude, unadjusted female strangulation rates for age and population group, and proportions of strangulation across specific circumstances of occurrence were compiled for each year and aggregated in some cases.</p> <p>Results</p> <p>This study reports that female homicidal strangulation in urban South Africa ranges from 1.71/100 000 to 0.70/100 000. Rates have generally declined in all the cities, except Cape Town. The highest rates were reported in the over 60 and the 20 to 39 year old populations, and amongst women of mixed descent. Most strangulations occurred from the early morning hours and across typical working hours in Johannesburg and Durban, and to a lesser extent in Cape Town. Occurrences across Johannesburg, Durban and Pretoria were distributed across the days of the week; an exception was Cape Town, which reported the highest rates over the weekend. Cape Town also reported distinctly high blood alcohol content levels of strangulation victims. The seasonal variation in strangulation deaths suggested a pattern of occurrence generally spanning the period from end-winter to summer. Across cities, the predominant crime scene was linked to the domestic context, suggesting that perpetration was by an intimate partner or acquaintance.</p> <p>Conclusion</p> <p>The study contributes to an emerging gendered homicide risk profile for a country with one of the highest homicide rates in the world. The results support the call for the development of evidence-based and gender-specific initiatives to especially address the forms of violence that instigate fatalities.</p