Condon, William, and Diane Kelly-Riley. "Assessing and Teaching What We Value: The Relationship between College-level Writing and Critical Thinking Abilities." Assessing Writing 9 (2004): 65-75. OhioLINK Electronic Journal Center. Web. 14 Nov. 2011.
Many scholars seem to just assume that writing promotes critical thinking, akin to a faithlike belief in a higher, supernatural power, but don't provide compelling evidence and explanations of how that can be done. Fortunately, in a study conducted at Washington State University (WSU), Condon and Kelly-Riley actually investigated the link between critical thinking and writing. Unfortunately, they found bad news for the "If they write it, then they will critically think" crowd. They looked at student writing using a critical thinking rubric called "The WSU Guide to Rating Critical Thinking." Some classes had incorporated the guide into instruction, and, probably not surprisingly, those classes showed better critical thinking than classes which did not use the guide. What was surprising, however, was that the classes that showed better critical thinking also showed worse writing and vice versa. The authors note, "The inverse correlation, [sic] and then the lack of relationship between our writing assessment scores and critical thinking scores point to what anecdotal evidence has long supported. Oftentimes, raters in our Writing Assessment Program comment that the exams seem to show sound writing abilities, but really contain no critical thought, or are vacuous or superficial. Haswell's research (1991) indicates that when writers take risks with new ways of thinking, often their writing breaks down in structure as the student grapples with a new way of thinking" (65-66). The authors thus suggest that writing alone will not promote critical thinking. What will promote critical thinking includes explicitly laying out expectations for students including values and features of the individual discipline being taught (65).
Ultimately, the authors argue that "Writing acts as a vehicle for critical thinking, but writing is not itself critical thinking" (66). They provide helpful advice for how to promote critical thinking in the classroom, most of which involves explicitly clarifying expectations for critical thinking (66). The authors also go on to discuss issues with using timed writing situations to assess anything beyond superficial writing traits (67-68). Though writing clearly has a place in using courses to promote critical thinking, writing by itself isn't a substitute for the critical thinking, and instructors should be careful to assess the thinking and not just the writing.
The article is available in the OhioLINK Electronic Journal Center.