To arrive at these conclusions, Professor Ryan Schacht of the University of Utah in Salt Lake City undertook analysis of sex ratio data from each of the 3082 counties that make up the U.S. This information was taken from the U.S. Census Bureau. The information about gender ratios was then compared with crime data (taken from statistics compiled by the U.S. Federal Bureau of Investigation.) The data search was confined to ‘younger’ people, that is women and men of reproductive age.
The crimes considered were murder, assault, rapes, sex offences and prostitution. Normalizing the data for poverty (which has an association with crime), the data revealed that rising proportions of men in a given county correlated with fewer male initiated crimes, and conversely a more even gender mix or increasing levels of women led to a an increased tendency for male initiated crimes to occur. The researchers hope the findings will inform crime prevention strategies.
As to why this is, the researchers apply psychology. Here they argue, as New Scientist reports, when women are fewer in number men need to be more dutiful to win and retain a partner (in the context that excessive male violent behavior is off-putting to many women.) With this Professor Schacht reasons “when women are abundant, men become less committed to single partners and more interested in pursuing multiple relationships. This brings men into conflict with each other in response to their more uncommitted, promiscuous mating orientation.”
The research is published in the journal Human Nature, in a paper titled “Marriage Markets and Male Mating Effort: Violence and Crime Are Elevated Where Men Are Rare.”
Importantly, the finding is based on the U.S., which means that there is a cultural and geographic context to the findings and they may not be applicable to other societies.
