Investigated in this study was the relationship between an inquiry approach to science instruction and language development. Four classes of sixth-grade children from two socioeconomic groups participated in the study. The treatment consisted of 12 inquiry film sessions and six discussion sessions, each session 40 minutes in length. At the end of each film session, the students wrote as many hypotheses as they could in 12 minutes. Collected papers were scored on two criteria: (1) the Hypothesis Quality Scale, and (2) the Syntactic Complexity Formula. Results of a statistical correlation study indicated high correlation between hypothesis quality scores and syntactic complexity for treatment groups in both socioeconomic levels. It is concluded that the link between the formation of scientific hypotheses and language development is cognitive development. Implications are discussed regarding the popular view that successful individuals in science are not generally proficient in language-centered activities. (CS)