That has a very official-sounding name in statistics: "Going fishing."
The rule, in statistics, as in science, is you start with a hypothesis, and you test that specific hypothesis. If you feed a system endless amounts of data, it will find a correlation somewhere. That 95% correlation means there's a 95% chance of that correlation being valid; if you've tested for more than 20 correlations, you have around even odds of having found one.
However, in this case the scientists have done their homework; they ran their tests, and then sought out other data sets to examine as well. Rick Nevin, one of the statisticians doing the research, has run the data on nine countries, and found strong correlations. Jessica Reyes, another statistician, ran the data on different states, comparing states on the basis of leaded gasoline phase-outs (different states followed different schedules on eliminating leaded gasoline); it tracked exceptionally well. There have been hundreds of citations and follow-ups on their work, and only one study out of all of them contradicted the findings. (And, for what it's worth, that study was funded by the largest lead fuel additive company, and engages in a lot of statistical hijinx, some of which are mentioned elsewhere in this thread.)
Moreover, studies performed have shown demonstrably higher blood levels in criminals than in the general population. The link between lead and aggressive behavior has long been known, as well as its effect on intelligence. Neurologist David Bellinger is one of hundreds of individuals who has published studies on the subject.
Unfortunately, virtually all of these studies are behind paywalls, so unless you have access to a university library I can't give them to you to examine yourself.
Of the nine countries Nevin studied, the same; the variable tracked for 60-90% of crimes given a 23-year lead time. (That's the error bar, I believe, meaning lead was predictive of somewhere between 60-90% of the crime, which is a fancy way of saying that 10-40% of the crime rate either had nothing to do with lead or the signal was too weak to identify.)
While everyone else wants to bitch and gripe over whether or not such contamination really does yield higher crime rates and lower IQ's, I am simply relieved to see conservatives looking for alternative methods of solving crime that do not involve being a police statocracy.
If you're referring to me, I'm not really conservative. I'm middle-libertarian; I could be convinced on things like the death penalty (which I'm weakly for, at the moment, although I'd prefer a substantially stronger burden of evidence), favor a middle ground on intellectual property (down with software patents, for one!), and favor certain kinds of redistribution (I believe the government should be limited to taxing land (and land only, not the improvements placed upon it), and don't believe in the current welfare state, but do believe excess funds from aforementioned property taxation should be distributed evenly across the population). I also tend to be for certain kinds of regulation (of the "do no harm" variety, not the "in society's interests" variety), but regard these as -usually- being better served by tort law.
Oh, actually I was referring to the objectivist mentioned in the title of this thread.
Issues such as capital punishment are matters of a libertarian-authoritarian scale (specifically civil libertarianism), rather than a left-right scale. However being opposed to patent restrictions may put you closer to the individualist/general market-libertarian spectrum of things, rather than the libertarian-capitalist spectrum. So perhaps center-right? To be honest what you advocate sounds strongly reminiscent of Geonomics. Regardless I would most certainly not consider you a 'middle-libertarian' based on our past discussions. Centrists on the libertarian scale are mutualists, syndicalists and the like who advocate a blend free market economies with common ownership of the means of production and co-operative living.
When you say, "of the 'do no harm' variety", I assume you mean actions which violate natural law; the right to be free from the threat of murder, rape, assault, libel and fraud?