MR, SAT, crime, and unwed pregnancy trends show the relationship between preschool blood lead and multiple manifestations of the specific outcome of lead-induced neurobehavioral damage, reflecting impacts across the preschool blood lead distribution.  The 1936-1990 average blood lead trend reflects a temporal shift in the entire preschool blood lead distribution, including a rise and fall in severe lead poisoning prevalence especially associated with MR and violent crime, and in marginally elevated blood lead prevalence associated with marginally lower IQ and academic achievement.