There is historical and empirical evidence suggesting that smaller class sizes, particularly around 12 students or less, can have several benefits. For an area of teaching and learning so impactful, the dearth of research sometimes feels stunning. While few schools hold or research the impacts of smaller classes, progress has been made. 

Consider Edward Hall’s fascinating read, Beyond Culture:

Fortunately, something is known both empirically and scientifically about the influence exerted by size on groups and the effect of size on how the groups perform. Research with business groups, athletic teams, and even armies around the world has revealed there is an ideal size for a working group. This ideal size is between eight and 12 individuals. This is natural, because man evolved as a primate while living in small groups… Eight to 12 persons can know each other well enough to maximize their talents. In groups beyond this size, the possible combinations of communication between individuals get too complex to handle; people are lumped into categories and begin the process of ceasing to exist as individuals. … Participation and commitment fall off in larger groups — mobility suffers; leadership doesn’t develop naturally but is manipulative and political.

Larry Cuban at Stanford presented research showing that student performance did not improve significantly until classes fell under roughly 15 students, i.e., Socratic, and did not get much worse until they rose above 30. At Grauer, our decades-old efforts to cap classes have led to constructive observations warranting further study.  

There is historical and cultural significance of groups consisting of 12 individuals in various traditions, religious contexts, and symbolic systems. The number 12 has often been associated with completeness, balance, and a manageable size for effective communication and collaboration. Consider: the twelve Apostles in Christianity, the twelve Knights of the Round Table, the twelve Olympians in ancient Greek mythology, the twelve tribes of Israel, and the twelve Zodiac signs each associated with different attributes. On an anecdotal level, I have consistently found that, with classes of 7 to 12, the attributes of my students, and many of my associate teachers have found this to be true. Each class size has attributes in need of study.


Grauer Class Size Categories:

  • 1–3  Tutoring
  • 4–14 Socratic/small class
  • 15–20 Small-medium class
  • 20–30 Medium-sized class
  • 31+ Large class or lecture

We note that teachers with medium and large classes tend to naturally divide their classes into sections of two or three to create a setting for collaborative learning. Students in small-medium classes have more teacher attention but cannot have a seminar environment where everyone can be expected to be accountable and present. Distractions increase as we add students. Attention spans wane as students are farther than 12 feet from the teacher, and there are fewer opportunities for active participation above the Socratic class levels. Additional classroom rules and regulations necessary as classes grow larger impact creativity, individuality is limited, and prepackaged, timed curricular systems supplant the primacy of authentic human discourse. 

Though not much research has been done, what there is supports the above historical and anecdotal evidence. The Oxford Center for Staff and Learning Development found that, “in the case of led groups, as for academic discussion, the maximum for member satisfaction according to students (NUS 1969) is 10 to 12.”


Key findings from research studies:


Academic Achievement

A study conducted by Jeremy Finn and Charles Achilles (2012) analyzed data from the Tennessee STAR project, a large-scale experiment that randomly assigned students to small classes (13–17 students) or regular-sized classes (22–25 students) in kindergarten through third grade. The study found that students who were in small classes performed better academically in the early grades and continued to outperform their peers in subsequent years. The positive effects were particularly pronounced for disadvantaged students.

A meta-analysis conducted by Hattie (2009) found that smaller class sizes have a positive impact on academic achievement. The study revealed that reducing class size can lead to increased student achievement across various subjects and grade levels.

Student Engagement

A meta-analysis by Robert Pianta and colleagues (2009) examined the impact of class size on student engagement and found that smaller classes were associated with increased student engagement, participation, and interaction with teachers and peers. This higher level of engagement can lead to enhanced learning experiences and greater student achievement.

Research by Finn and Achilles (1999) showed that students in smaller classes tend to be more engaged and participate more actively in classroom activities. With fewer students, teachers can provide individual attention and create a more interactive learning environment.

Classroom Environment

A study by Diane Whitmore Schanzenbach (2014) analyzed the effects of class size reduction on classroom environments in the early grades. The research showed that smaller classes promoted a more positive and productive classroom climate, with increased opportunities for individualized instruction, personalized feedback, and student-teacher interactions.

Several studies have found that smaller class sizes are associated with improved student behavior and reduced disciplinary issues. A study by Mosteller (1995) found that students in smaller classes demonstrate fewer disruptive behaviors, leading to a more positive and focused classroom environment.

Teacher-Student Relationships:

Smaller class sizes facilitate stronger teacher-student relationships. A study by Frederick Mosteller (1995) examined the impact of reducing class sizes in early grades and found that teachers in smaller classes were better able to establish supportive and positive relationships with their students. These relationships can lead to improved student motivation, engagement, and social-emotional development.

A study by Blatchford, Bassett, and Brown (2008) demonstrated that smaller class sizes allow for more frequent and meaningful interactions between students and teachers. This increased interaction can foster stronger relationships, personalized instruction, and greater support for students’ individual needs.

Long-Term Benefits:

Research by Alan Krueger (2003) examined the long-term effects of class size reduction in early grades and found that students who had smaller classes in their early years of schooling were more likely to graduate from high school, attend college, and have higher earnings as adults compared to those who were in larger classes.

It’s important to note that while these studies provide evidence for the benefits of smaller class sizes, many do not focus specifically on class sizes of 12 or less. Given the potential for positive impacts on student outcomes, more research would be extremely welcomed by many, especially small schools practitioners.

Pin It on Pinterest

Share This