Recent studies have examined how individual differences interact with language choice and achievements. This study analyzes how students' cognitive skills and achievements in English and German reading comprehension depend on parents' level of education. In 2015 data were collected in the Hungarian Educational Longitudinal Program from representative samples of 8th graders A total of 1334 students learned English and 609 learned German. Online tests assessed students' reading comprehension in English and German, their L1 reading comprehension, inductive reasoning and SES. Children of more educated parents tend to choose English. However, in contrast with earlier research, no significant difference was found between the aptitude levels of the two groups. The impact of background variables is stronger in the group studying English. Mothers’ education correlates more strongly with reading comprehension achievements in English (r = 0.401) than in German (r = 0.192). Regression analyses indicate that the impact of inductive reasoning is stronger than that of SES. A stronger relationship was found between inductive reasoning and English reading test results (r = 0.570) than with German reading (r = 0.454). Background variables influence development in English and German differently. Inductive reasoning plays a more important role in studying English, whereas L1 reading comprehension achievements more greatly impact reading in German.