What the Research Says About Debate for Students

The short version

• The strongest evidence concerns reading and English test scores among middle and high school students in US urban policy-debate programs. One carefully designed study in Boston found a modest gain.
• Studies in Chicago and Houston link debate to higher graduation rates, test scores and college readiness. These are associations. Students who choose debate may already differ from those who don’t.
• No randomized trial of competitive debate in grades 4–12 was found in the research reviewed for this article.
• Evidence for younger children (grades 4–5), confidence, media literacy and civic engagement is thin, indirect or missing.

First, what kinds of evidence are there?

Research on school activities usually falls into three groups.

Randomized trials assign students to an activity by chance, so the two groups should be alike at the start. This is the most reliable way to show that an activity causes a result.

Quasi-experimental studies have no random assignment, but use statistical designs, such as following the same students before and after they join and comparing them with similar students elsewhere, to reduce the effect of pre-existing differences.

Observational studies compare students who took part with students who didn’t, and adjust for what the researchers can measure. They can show that two things go together. They cannot, on their own, show which one caused the other.

The distinction matters for debate because families, not researchers, decide who joins. Students who volunteer for debate may be more motivated or better prepared to begin with. Researchers call this selection bias, and nearly all the debate research below has to deal with it.

Reading and English scores: the Boston study

The most rigorous debate study found so far was published by Beth Schueler and Katherine Larned in 2023. They followed 3,515 students in Boston Public Schools who took part in policy debate at some point between the 2007–08 and 2016–17 school years. Policy debate is an extracurricular activity focused on critical thinking, argumentation and policy analysis. The schools served many students from low-income families.

The researchers compared students’ test scores before and after they joined, and they treated students in schools that never joined the debate league as the most useful comparison group. They found:

• English language arts (ELA) scores rose by about 0.13 standard deviations. A standard deviation is a common way to compare test results across groups. The authors describe this gain as equal to about two-thirds of a year of average ninth-grade learning, which is a modest effect, not a dramatic one.
• The gain was concentrated in reading. The reading subskill rose by about 0.10 standard deviations and was statistically significant. The language subskill (grammar and usage) rose by about 0.06, which was not.
• Math, attendance and discipline showed no harm. The math estimate was positive but not consistently significant.
• Gains were largest for students who scored lowest before joining. Students in the bottom quarter of baseline scores gained about 0.24 standard deviations, compared with about 0.10 for the top quarter. The direction was positive for every group.

The study also has limits, and the authors state them. Students were not randomly assigned, so other changes in a student’s life over the same years cannot be fully ruled out. There was no information on other activities students joined. Most students began debating in ninth grade, only 28% ever took part in middle school, and most participated for just one year. Boston was the only district studied, and the format was policy debate.

The authors also report positive estimates for high school graduation and college enrollment. They write that they are “not able to rule out the possibility that some or all” of those effects come from selection bias, and that the estimates “could be inflated.” The reading result is the stronger finding.

Graduation and college readiness: Chicago and Houston

Several studies of the Chicago Debate League found that debaters graduated and met college-readiness benchmarks at higher rates than their classmates.

One of the largest, by Susannah Anderson and Briana Mezuk (2012), covered 12,179 Chicago Public Schools students from 1997 to 2007, including 2,449 debaters. After adjusting for a risk index and demographics, the odds of graduating were about 3.1 times higher for debaters. Debaters were also more likely to reach ACT college-readiness benchmarks in English, reading and science. Students who debated more rounds tended to do better.

It would be a mistake to read this as “debate makes students three times as likely to graduate.” The odds figure is a statistical comparison, not a promise, and the students were different from the start. Debaters had higher eighth-grade test scores, and 8.4% of them had received special education services, compared with 16.0% of non-debaters. The authors say so directly: “Without a randomized controlled experiment it is impossible to assess the degree of this bias.” The finding that more rounds went with better results is open to the same objection, because motivated students may both stay longer and do better.

A study of Houston high schools (Ko and Mezuk, 2021; 35,788 students, 1,145 of them debaters) found a similar pattern of higher grades and SAT scores among debaters. It is another observational study, so it shows the pattern is not unique to Chicago but cannot show the cause.

The college evidence is mixed. A study of 6,411 Chicago graduates (Shackelford, ScottRatliff and Mezuk, 2019) found debaters were more likely to enrol in college, especially four-year colleges, and that this was largely explained by their ACT performance. Debate was not associated with a higher likelihood of finishing college.

Learning to argue: a middle school study

The research that speaks most directly to argument skills is a three-year study by Deanna Kuhn and Amanda Crowell at Columbia University’s Teachers College, published in 2011.

Starting in sixth grade, 48 students at an urban middle school took part in a structured program. In each unit they chose a side on a social issue, prepared reasons for their position, anticipated what opponents would say, and then debated in pairs through computer messaging, so the dialogue stayed on screen. A comparison group of 23 students had teacher-led class discussions and wrote more essays (14 a year, compared with four).

On new topics, the debate group wrote essays with more arguments that addressed the other side and tried to weigh both sides. They also listed more questions of substance, such as what information would help them make their case. According to the researchers, these skills do not routinely develop at this age on their own.

This is a small study at one school. Whole classes, not individual students, were assigned to groups, and the format was online paired dialogue rather than tournament debate. It suggests that structured argument practice can be taught and learned in the middle grades. It does not show what competitive debate does.

What about younger children?

No study found for this article tests debate in grades 4 or 5. The closest evidence is about classroom talk in general. The Education Endowment Foundation in England ran a randomized trial of “dialogic teaching” in Year 5 (roughly grade 4 in North America), in which teachers were trained to help pupils reason, discuss and argue rather than only answer questions. Across 76 schools and 4,985 pupils, children made about two additional months of progress in English and science and one in maths, and the evaluators were moderately confident the difference was due to the program. A follow-up published in 2019 found no effect on national tests a year later, although the evaluators noted that many schools probably did not continue the approach in Year 6.

This was whole-class teaching, not debate, and the gains did not last. It is a reason to take young children’s reasoning seriously, not evidence that debate works for them.

Confidence, media literacy and civic life

These are the benefits parents hear about most and the ones research has tested least.

• Confidence. A randomized study of Word Generation, a middle school literacy and discussion program (not debate), found that students reported more confidence discussing topics they had recently covered, but not topics from the previous year (Lin and colleagues, 2016). Surveys of debaters report perceived benefits or differences in communication measures (Littlefield, 2001; Howe and Cionea, 2021), but they rely on self-reports from people who chose debate, and the second involved adults.
• Media literacy. The Boston authors list the ability to tell fact from opinion as a question for future research. We found no study that tests whether debate improves media literacy in grades 4–12.
• Civic engagement. A randomized study of 341 university students found that a controversial-debate curriculum had no effect on political interest (Sanjuan and Mantas, 2022). That was a different age group and format, but it means this benefit should not be assumed.

Each of these may be real. None has been shown for debate in grades 4–12.

Summary of the evidence

What this means for families

Look for the skill, not the slogan. The best-supported findings involve practising specific things: building a case from evidence, answering the other side and explaining reasoning aloud. Ask any program which of these children actually practise.

Be careful carrying results to a new setting. The debate studies here come from US urban school districts and mostly from policy debate. They did not examine Canadian students or other formats, such as World Schools, Public Forum or parliamentary debate.

Expect gains to be modest and gradual. The best-designed result, 0.13 standard deviations, is meaningful but small, and most students in that study took part for a single year.

Apply the same questions to every claim. When a program quotes a statistic, ask who was studied, how participants were chosen, and whether the study can show cause or only association.

Open questions

Researchers have not yet answered whether debate benefits students in grades 4–5, whether results in US policy debate hold in other formats and countries, whether confidence and media literacy improve, or whether gains last beyond one or two years. A randomized trial would help answer several of these questions. Until one exists, careful claims are the honest ones.

A note on the sources

The Boston study was funded by the Smith Richardson Foundation. The Anderson and Mezuk paper is available through Chicago Debates, an organization that supports debate programs. Neither fact invalidates the research, but readers should know about both.

References

1. Schueler, B. E., & Larned, K. E. (2023). Interscholastic policy debate promotes critical thinking and college-going: Evidence from Boston Public Schools. Educational Evaluation and Policy Analysis, 47(1), 108–134. https://doi.org/10.3102/01623737231200234 (working paper, August 2023: https://files.eric.ed.gov/fulltext/ED639157.pdf)
2. Anderson, S., & Mezuk, B. (2012). Participating in a policy debate program and academic achievement among at-risk adolescents in an urban public school district: 1997–2007. Journal of Adolescence, 35(5), 1225–1235. https://chicagodebates.org/wp-content/uploads/2025/04/Anderson-Mezuk-2012.pdf
3. Ko, T. M., & Mezuk, B. (2021). Debate participation and academic achievement among high school students in the Houston Independent School District: 2012–2015. Educational Research and Reviews, 16(6), 219–225. https://doi.org/10.5897/err2021.4137
4. Shackelford, T. D., ScottRatliff, M., & Mezuk, B. (2019). Participating in a high school debate program and college matriculation and completion: Evidence from the Chicago Debate League. Educational Research and Reviews, 14(11), 397–409. https://files.eric.ed.gov/fulltext/EJ1218569.pdf
5. Kuhn, D., & Crowell, A. (2011). Dialogic argumentation as a vehicle for developing young adolescents’ thinking. Psychological Science, 22(4), 545–552. https://doi.org/10.1177/0956797611402512 ; Association for Psychological Science (2011, March 11). Why argue? Helping students see the point. https://www.psychologicalscience.org/news/releases/why-argue-helping-students-see-the-point.html
6. Education Endowment Foundation. Dialogic Teaching: trial (independent evaluator: Sheffield Hallam University; completed July 2017; addendum April 2019). https://educationendowmentfoundation.org.uk/projects-and-evaluation/projects/dialogic-teaching
7. Lin, A. R., Lawrence, J. F., Snow, C. E., & Taylor, K. S. (2016). Assessing adolescents’ communicative self-efficacy to discuss controversial issues: Findings from a randomized study of the Word Generation program. Theory & Research in Social Education, 44(3), 316–343. https://doi.org/10.1080/00933104.2016.1203852
8. Sanjuan, R., & Mantas, E. M. (2022). The effects of controversial classroom debates on political interest: An experimental approach. Journal of Political Science Education, 18(3), 343–361. https://doi.org/10.1080/15512169.2022.2078215
9. Littlefield, R. S. (2001). High school student perceptions of the efficacy of debate participation. Argumentation and Advocacy, 38(2), 83–97. https://doi.org/10.1080/00028533.2001.11821559
10. Howe, W. T., & Cionea, I. A. (2021). Exploring the associations between debate participation, communication competence, communication apprehension, and argumentativeness with a global sample. Argumentation and Advocacy, 57(2), 103–122. https://doi.org/10.1080/10511431.2021.1897274