The purpose of this investigation was to examine the relational reasoning performance of three groups from South Korea who either differed significantly in age or in the timing of their education. One group consisted of 200 sixth-grade adolescents. The other groups were composed of older adults who either attended school during the mandated timeframe (typical, n = 34) or who are only now enrolled in a secondary-school program (atypical, n = 45). Our quantitative investigation of the participants' performances on the Test of Relational Reasoning-Junior showed that the atypically schooled older adults performed significantly below the young adolescents and typically schooled peers on the composite scores and on all four scales (i.e., analogical, anomaly, antinomy, and antithesis). Further, the semi-structured interviews elaborated on social conditions pertinent to the quantitative analyses. Overall messages shown in the data about relational reasoning development and the potential contributions of educational and social factors are discussed.