Growing up in a Spanish-speaking household one of the authors, Ann, was subjected to an ample variety of “dichos”, or sayings, with nuanced meanings.  She was repeatedly warned against laziness and lying. Her mother was very concerned about who she spent time with and would frequently say “Dime con quién andas, y te diré quién eres” (“Tell me who your friends are and I’ll tell you who you are.”) She certainly didn’t know it but she was referring to the similarity/attraction effect!

Similarity/attraction theory suggests that people are most attracted to those who share similar traits. People prefer to affiliate with those who share similar attitudes, personalities, physical attributes, and a host of other characteristics (Luanay & Dunbar, 2015). Like magnets, there is a strong attractive  force between similar poles that resists separation.  Similarity effects tend to be strongest and most consistent for attitudes, values, activity preferences, and attractiveness.

This could help to explain why Hattie (2009) found that student-teacher relationships have a very high effect size on student achievement.  Research shows that positive teacher-student relationships (TSRs) support students’ adjustment to school, contribute to their social skills, promote academic performance, and foster students’ resiliency in academic performance. Strong teacher-student relationships can even act as a buffer against the potentially adverse effects that insecure parent-child attachments can have on students’ academic achievement.

Knowing these positive impacts, Harvard researchers examined whether strong TSRs are simply a matter of chance or if they can be engineered and intentionally constructed (Gehlbach et. al, 2016). Specifically, the research examined whether perceptions of similarities across even trivial factors, such as hobbies, interests, or values, resulted in improved relationships between teachers and students. They hypothesized that if they could focus teachers’ and students’ attention on what they have in common so that they would perceive themselves as similar, they could create more positive relationships between teachers and students. The great news is that not only did they validate their hypothesis, but they discovered even more powerful effects related to student achievement.

Here’s what they did.  Students and teachers took a 28 item “get-to-know-you survey” during the first week of school.  The researchers then provided each teacher with a list of 5 things s/he had in common with each student.  Each student was also provided with a list of 5 things s/he had in common with the teacher. Following this simple ‘intervention’, all teachers reported improved TSRs with their students and the students earned higher quarterly grades compared to students whose teacher did not receive feedback on similarities. This was most significant among minority students (i.e., Black and Latino), whose grades increased by .4 of a letter grade. In the school in which the study was conducted, this academic achievement among minority students closed the achievement gap by about 60%!

In analyzing the data further, the researchers found that improved student achievement was correlated only to teachers’ perceptions of similarities with students, not to students’ perceptions. When teachers saw what they had in common with each student, not only did their sense of similarity with the student increase, but they also “perceived better relationships with those students, and those students earned higher course grades” (Gelbert et al, 2016, p. 342).

These research findings made us wonder whether one thing we could do in addressing the achievement gap would be to help teachers identify similarities that may not be immediately obvious between themselves and their students .  If you are interested in trying this out in your classroom or school, see the survey created by the researchers and related resources in the School Tools section above.

The sage advice that Ann’s mother shared with her years ago that we tend to gravitate toward, act like, and enjoy being around others whom we perceive as similar, turns out to be backed by social psychology research. What additional impact might Ann’s madre have had if she had shared with Ann’s teachers that her daughter likes mushroom, bacon, and onion pizza, describes herself as social and caring, learns best through teacher-led discussions, watches reality tv, and, if she won tickets to a championship sporting event, would give those tickets to someone who cares?   Ann Narcisse, Valedictorian?


Hattie, J. (2009), Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement. NY: Routledge.

Gelbach, H., Brinkworth, M. E., King, A. M., Hsu, L. M., McIntyre, J., & Rogers, T. (2016). Creating birds of similar feathers: Leveraging similarity to improve teacher-student relationships and academic achievement. Journal of Educational Psychology, 108 (3), 342-352.

Launay J, Dunbar RIM (2015) Playing with Strangers: Which Shared Traits Attract Us Most to New People?. PLOS ONE 10(6): e0129688.

Rudasill, K. M., Reio, T. G., Stipanovic, N., & Taylor, J. E. (2010). A longitudinal study of student-teacher relationship quality, difficult temperament, and risky behavior from childhood to early adolescence. Journal of School Psychology, 48(5), 389-412.