Unlike blood and urine, hair is suitable for the analysis of chronic, long-term exposures. William Walsh, an analytical chemist, began studying the role of body chemistry in violent behavior about 7 years ago. His first study involved 24 pairs of male siblings, one of whom was delinquent and violent and one of whom had never been in trouble. The hair from all 24 of the violent boys registered abnormal readings for all 11 elements which were found to be reliably measurable. In addition, the levels were nonrandom, falling into one of two distinct groupings. Both of the violent groups were extremely high, relative to normal individuals, in lead, cadmium, iron, and calcium, and extremely low in zinc. One group also showed high levels of sodium and potassium along with low levels of copper, while the other group showed just the reverse. None of the nonviolent siblings showed either of these patterns. The two trace-metal patterns among the violent siblings distinguished between episodic criminals and sociopaths as defined by sociologists and criminologists. A second study compared 96 extremely violent men with 96 nonviolent counterparts and produced similar results, except that 4 of the violent subjects had extremely low levels of all the nutrients. In another study, the cadmium level in hair correlated with the proportion of refined carbohydrates in the diet of 184 children studied. In a further study, drastic restrictions in the refined sugar in the diets of juveniles in a Virginia detention center was followed by a sharp drop in antisocial behavior. Trace metals and body chemistry may also correlate with certain diseases.