Are Democrats at risk of losing "law and order" issue to Donald Trump?

[JonLP24]

30. These things are complex with no easy answers

There are lead-crime links.

The lead-crime hypothesis arose out of the confluence of several events, primarily the decrease in crime rates in the 1990s and the reduction of environmental lead pollution in the 1970s.[56] After decades of relatively steady increases, crime rates in the United States started to sharply decline in the 1990s. The trend continued into the new millennium. Multiple possible explanations have come about, with academic studies pointing to complex, multifactorial causation as different social trends occurred at the same time.[46] The fact that in the United States anti-lead efforts took place simultaneously alongside falls in violent crime rates attracted attention from researchers. Changes were not uniform across the country, even while increasingly stringent Environmental Protection Agency rules went into force from 1970s onward. Several areas had far greater lead exposure compared to others for years.[46]

While there is strong evidence indicating that genetics influence the development of violent and aggressive behavior,[57][58] more recent attention has focused on environmental factors such as lead exposure.[59] Though there is anecdotal evidence suggesting that knowledge of a relationship between lead exposure and behavior dates back centuries,[26] direct observations would not be documented until the late 1800s.[60] Research in the mid-1900s observed that children previously treated for lead poisoning displayed a series of aberrant behaviors, including violence and aggression.[38] Further research has yielded similar results, finding that past lead exposure functions as a predictor for criminal activity.[4][61][62][63] Nation-wide analyses have also demonstrated positive associations between air-lead concentrations and measures of criminality and homicide.[1][64] A meta-analysis of studies examining the relationship between lead and conduct problems arrived at a similar conclusion, suggesting that the magnitude of the relationship between lead exposure and behavior is comparable to the relationship between lead exposure and I.Q.[3] While the scientific literature suggests there is a relationship between lead exposure and behavioral issues such as delinquency and criminality, directly relating these observations to the decrease in overall criminality is more difficult.

According to Jessica Wolpaw Reyes of Amherst College, between 1992 and 2002 the phase-out of lead from gasoline in the U.S. "was responsible for approximately a 56% decline in violent crime". While cautioning that the findings relating to "murder are not robust if New York and the District of Columbia are included," Wolpaw Reyes concluded: "Overall, the phase-out of lead and the legalization of abortion appear to have been responsible for significant reductions in violent crime rates." She additionally speculated that by "2020, all adults in their 20s and 30s will have grown up without any direct exposure to gasoline lead during childhood, and their crime rates could be correspondingly lower."[46] According to Reyes, "Childhood lead exposure increases the likelihood of behavioral and cognitive traits such as impulsivity, aggressivity, and low IQ that are strongly associated with criminal behavior".[46]

https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesis