The Science of Strong Teams: What Actually Works

Explore what peer-reviewed research says about team cohesion, psychological safety, and performance — and how to build those conditions into your workforce.

In today’s dynamic business environment, strong teams are not a luxury; they are a strategic imperative. Yet many organizations struggle to define what makes teams effective in practice, not just in theory. Peer-reviewed research over the past two decades has increasingly converged around a few core factors that consistently predict high performance: team cohesion, psychological safety, and shared goals. Understanding and operationalizing these concepts can yield measurable improvements in engagement, innovation, and execution.

Defining Team Cohesion

Team cohesion refers to the strength of relationships within a team and the commitment of team members to collective goals. It includes both social cohesion (how much individuals like and trust each other) and task cohesion (the shared commitment to the team’s work). Studies have found that cohesive teams are more resilient, adaptable, and productive, especially under pressure.

Carron, Brawley, and Widmeyer (1998) provided one of the foundational models for understanding team cohesion, emphasizing that cohesion is multidimensional and context-dependent. In organizational settings, cohesion has been positively linked to performance across industries, particularly in teams that require high levels of interdependence (Beal et al., 2003).

However, cohesion without clarity can be misleading. Teams that are socially close but lack shared accountability can underperform. Thus, cohesion must be paired with strong goal alignment and clear expectations.

The Role of Psychological Safety

Psychological safety—defined by Harvard professor Amy Edmondson as “a shared belief that the team is safe for interpersonal risk-taking”—has emerged as a central variable in effective team dynamics. In psychologically safe environments, employees feel comfortable asking questions, admitting mistakes, or offering dissenting views without fear of embarrassment or retribution.

The concept gained widespread visibility through Google’s Project Aristotle, which analyzed over 180 teams to determine what made the highest performers stand out. The most important predictor was not seniority, background, or even team structure—it was psychological safety (Rozovsky, 2015). Teams that felt safe to speak up were more effective, more innovative, and more resilient to stress.

Psychological safety has also been linked to learning behavior within teams. Edmondson’s 1999 study showed that teams with higher psychological safety reported more errors—but also learned faster and performed better over time. This finding underscores that safety leads to transparency, and transparency fuels growth.

Linking Cohesion, Safety, and Performance

When cohesion and psychological safety work together, teams become significantly more capable of navigating uncertainty, integrating diverse perspectives, and executing complex tasks. A 2021 meta-analysis by Frazier et al. found that psychological safety was strongly correlated with performance, especially when teams had a high degree of interdependence and were tasked with problem-solving.

Importantly, cohesion can support the development of psychological safety by fostering trust and mutual understanding. At the same time, psychological safety can accelerate cohesion by encouraging open communication and vulnerability. These two dynamics reinforce each other, creating what researchers call a virtuous cycle of performance (Newman et al., 2017).

Operationalizing the Research: What Leaders Can Do

Understanding these concepts is important, but translating them into daily practice is where most organizations fall short. Below are several evidence-based strategies leaders can use to build stronger, safer, and more cohesive teams.

1. Model Inclusive and Vulnerable Leadership

Leaders set the tone for team behavior. Research consistently shows that when leaders admit mistakes, ask for input, and acknowledge uncertainty, teams respond with greater openness and engagement (Detert & Burris, 2007). This is not a call for performative humility, but for consistent modeling of behavior that invites contribution.

2. Structure Communication for Candor

Psychological safety does not mean the absence of tension—it means the presence of trust when tension arises. One way to support this is through structured communication routines such as retrospectives, after-action reviews, and rotating facilitation in meetings. These practices help ensure that all voices are heard and that disagreement becomes a tool for refinement, not conflict.

3. Align on Purpose and Process

Cohesion improves when team members understand not just what they are working toward, but how their work fits into the bigger picture. Regularly revisit team goals, clarify decision-making norms, and make interdependencies explicit. This builds what Hackman (2002) referred to as “enabling conditions” for team effectiveness.

4. Invest in Relationship Capital

Especially in distributed teams, it is easy to focus exclusively on task coordination. However, research suggests that investing in informal connections—whether through virtual coffee chats, peer recognition programs, or offsites—can significantly boost both social cohesion and team performance (Bartel et al., 2012). Relationship-building is not extra; it is foundational.

5. Measure and Adapt

Finally, psychological safety and cohesion can and should be measured. Tools like Edmondson’s Team Psychological Safety Scale or simple pulse surveys can offer regular insight into team dynamics. More importantly, teams should be encouraged to reflect on these results and co-create strategies for improvement.

Challenges and Cautions

While cohesion and psychological safety are powerful predictors of team performance, they are not universal cures. For example, highly cohesive teams can become insular or resistant to change, a phenomenon known as groupthink (Janis, 1982). Likewise, excessive emphasis on safety can dampen urgency or accountability if not balanced with clarity and performance standards.

Therefore, leaders must balance safety with stretch, cohesion with curiosity, and trust with rigor. This balance is not static but must be actively maintained as teams evolve.

Conclusion

Peer-reviewed research is clear: teams thrive when cohesion and psychological safety are present. These factors are not “nice-to-haves,” but strategic levers that drive innovation, resilience, and long-term performance. The organizations that invest in building these conditions intentionally—and continuously—are the ones most likely to succeed in the face of complexity.

In a time when collaboration is both more distributed and more critical than ever, the science offers a hopeful message. High-performing teams are not just born. They are built—with intention, with evidence, and with the everyday practices that research has shown to work.

References

• Beal, D. J., Cohen, R. R., Burke, M. J., & McLendon, C. L. (2003). Cohesion and performance in groups: A meta-analytic clarification of construct relations. Journal of Applied Psychology, 88(6), 989–1004.

• Bartel, C. A., Wrzesniewski, A., & Wiesenfeld, B. M. (2012). Knowing where you stand: Physical isolation, perceived respect, and organizational identification among virtual employees. Organization Science, 23(3), 743–757.

• Carron, A. V., Brawley, L. R., & Widmeyer, W. N. (1998). The measurement of cohesiveness in sport groups. In J. L. Duda (Ed.), Advances in Sport and Exercise Psychology Measurement.

• Detert, J. R., & Burris, E. R. (2007). Leadership behavior and employee voice: Is the door really open? Academy of Management Journal, 50(4), 869–884.

• Edmondson, A. C. (1999). Psychological safety and learning behavior in work teams. Administrative Science Quarterly, 44(2), 350–383.

• Frazier, M. L., Fainshmidt, S., Klinger, R. L., Pezeshkan, A., & Vracheva, V. (2021). Psychological safety: A meta‐analytic review and extension. Personnel Psychology, 74(1), 1–49.

• Hackman, J. R. (2002). Leading Teams: Setting the Stage for Great Performances. Harvard Business Press.

• Janis, I. L. (1982). Groupthink: Psychological studies of policy decisions and fiascoes. Houghton Mifflin.

• Newman, A., Donohue, R., & Eva, N. (2017). Psychological safety: A systematic review of the literature. Human Resource Management Review, 27(3), 521–535.

• Rozovsky, J. (2015). The five keys to a successful Google team. re:Work. Retrieved from: https://rework.withgoogle.com/blog/five-keys-to-a-successful-google-team/