This study reports on a bilingual survey of Japanese children (7-12 years old) at Boston Japanese School. The objective of the paper is to propose some factors that foster cognitive academic language proficiency (CALP) in Japanese and English. The following factors are thought to promote CALP acquisition: L1 maintenance and use in the home, individual intelligence, prior overseas experiences, reading, positive attitude and length of stay in the host culture, coupled with early age of arrival. It is found that strong supports in the home helps generate a favorable language environment that enhances CALP development. The paper bases its results on data collected via the Oral Proficiency Assessment for Bilingual Children.
