Abstract: | The purpose of the present study was to measure the effects of language proficiency and grade (age) on the reasoning of Puerto Rican bilingual children in elementary school. 20 syllogisms were administered, 10 in English and 10 in Spanish, and accuracy of and strategy for solution were examined. Solutions were more often accurate, and the proportion of theoretical explanations given for them was higher in Spanish. Differences by grade were not significant except a higher proportion of theoretical explanations were given by children in Grade 5 for syllogisms in Spanish. |