Student-active science teaching that includes interactions among students is suggested to support students' reasoning skills. However, little is known about what are the beneficial modes of interaction to support learning. In the present study, we investigated how different types of classroom discussion on socioscientific issues can encourage students' reasoning skills as expressed in argumentative essays. Qualities of students' talk and reasoning skills were described in terms of attitudes, drawing on Dewey, and sociolinguistic codes, drawn from Bernstein. Qualitative data consisting of transcribed classroom discussions and student argumentative essays were analysed by means of statistical methods. The results describe how specific qualities in students' talk influence qualities of students' argumentative texts. The results indicate that teachers by promoting elaborate talk among students can stimulate more nuanced and elaborate student texts.