This chapter examines an antecedent variable that investigators of delinquency should take into account, but it is hard to think of age as a causal variable. Relations are examined within categories of antecedent variables, there is no way to determine which antecedent variable accounts for an observed difference, or, in fact, whether the relation is genuine or spurious. The direction of causation is clear in many of the relations Reiss presents; however, even complete inability to determine causal order would not have justified his failure to control antecedent variables. The Gluecks present their data in dozens of two-variable tables, in which delinquents are compared with nondelinquents. Many of the tables show strong relations between the independent variable and delinquency. Birth order may be significantly related to delinquency in the Gluecks' data, but this relation is almost certainly spurious.