Learn how Amy Edmondson's psychological safety research transforms team performance. Evidence-based strategies to build fearless, high-performing teams.
What if the most important factor determining your team's performance has nothing to do with talent, and everything to do with fear?
Harvard Business School professor Amy Edmondson's groundbreaking research on psychological safety fundamentally changed how organizations understand team effectiveness. Rather than expecting high-performing teams to report fewer mistakes, Edmondson discovered the opposite: teams that reported more errors were actually the highest performers. This counterintuitive finding revealed that psychological safety—the shared belief that team members can take interpersonal risks without fear of punishment or humiliation—is the foundation of high-performing teams. Decades of empirical research, including Google's Project Aristotle, confirm that psychological safety predicts team performance, innovation, and organizational outcomes more reliably than individual talent alone.
In the 1990s, Amy Edmondson conducted a landmark study in hospital settings to understand the relationship between medical errors and teamwork. She hypothesized that the best-performing nursing teams would report fewer mistakes. Her data revealed something entirely different: higher-performing teams reported more errors than lower-performing teams.
This paradox forced Edmondson to reconsider what the data meant. The breakthrough insight was elegantly simple: better teams don't make more mistakes. They're simply more willing and able to talk about them.
This observation led to her groundbreaking 1999 research published in Administrative Science Quarterly, which introduced the concept of psychological safety. She defined it as "a shared belief that the team is safe for interpersonal risk-taking—that team members can speak up with ideas, questions, concerns, or mistakes without fear of being punished or humiliated."
The implications were profound. Psychological safety wasn't about being nice or avoiding accountability. Rather, it enabled the open communication, error acknowledgment, and continuous learning that distinguish exceptional teams from mediocre ones.
Psychological safety is often confused with trust, but the two are distinct concepts. Trust is about how one person views another—whether you believe a colleague will follow through on commitments. Psychological safety, by contrast, is a collective belief about group norms—what it means to be a member of this team and how others will react when you take interpersonal risks.
In a psychologically safe team, members feel confident that they can:
Ask for help without being seen as incompetent
Admit mistakes without facing punishment or humiliation
Raise concerns about safety, ethics, or strategy without retaliation
Suggest ideas, even immature or novel ones, without ridicule
Challenge the status quo and respectfully question authority
Be themselves without fear of being marginalized
Edmondson emphasizes that psychological safety does not mean low accountability or avoiding difficult conversations. In fact, the highest-performing teams combine psychological safety with high performance standards. The two are complementary, not contradictory. Safety enables honest conversations about what isn't working; accountability ensures those conversations lead to performance improvement.
Edmondson's framework maps teams across two dimensions: psychological safety and accountability. This creates four distinct performance zones:
The Learning Zone (High Safety, High Accountability): Teams that innovate, learn rapidly, and deliver excellent results. Members feel safe to experiment and learn from failures because mistakes are treated as learning opportunities rather than failures requiring blame. Performance standards remain high and uncompromising.
The Apathy Zone (Low Safety, Low Accountability): Teams where members do minimal work and show little care about outcomes. Without safety, people disengage. Without accountability, there's no motivation to improve.
The Anxiety Zone (High Accountability, Low Safety): Teams focused on avoiding blame and looking good rather than solving problems. Members hide mistakes, avoid taking risks, and perform routine work with minimal innovation. High stress, low innovation.
The Comfort Zone (High Safety, Low Accountability): Teams where people are pleasant and relaxed but underperforming. Members might feel free to speak but lack the drive to excel.
The highest-performing organizations deliberately cultivate the Learning Zone—combining genuine psychological safety with clear performance expectations.
Edmondson’s original hospital study found that the highest-performing nursing teams reported approximately 25% more medication errors in their self-reports, not because they made more mistakes, but because they were more willing to document, discuss, and learn from them. When clinicians later interviewed these teams, they found something remarkable: high-performing teams were actively catching and correcting errors through open communication. Lower-performing teams were not making fewer errors. They were making them silently, without reporting or learning.
In 2012, Google launched Project Aristotle, an extensive internal research initiative whose findings were published and widely shared beginning in 2015. The project analyzed more than 250 team variables across over 180 teams and identified five characteristics that distinguished high-performing Google teams:
Psychological safety, identified as the most critical factor
Dependability
Structure and clarity
Meaning of work
Impact of work
Google’s research concluded that psychological safety was far more important than the other four factors. In teams lacking psychological safety, even highly capable engineers hesitated to contribute ideas, ask questions, or admit mistakes. In contrast, teams with high psychological safety enabled even extremely smart, high-powered employees to contribute their full talents.
South Korean Sales and Service Teams (2020): A study of 104 field sales and service teams (529 employees) examined how psychological safety leads to team effectiveness. Key findings:
Psychological safety did not directly affect team effectiveness (β = 0.037, not significant)
However, psychological safety strongly predicted team learning behavior (β = 0.747)
Psychological safety predicted team efficacy (belief in the team's ability, β = 0.596)
Team learning behavior and team efficacy fully mediated the relationship between psychological safety and team effectiveness
Team efficacy was the strongest predictor of performance (β = 0.694)
This research revealed that psychological safety is the "engine" of performance, not the fuel. It activates team processes—learning and efficacy development—that drive actual performance.
High-Tech Companies in China (2024): A study of 580 employees across multiple high-tech enterprises examined how psychological safety drives innovation. Results:
Three dimensions of psychological safety all predicted employee innovative performance:
Team collaboration and understanding (β = 0.247***)
Team information sharing (β = 0.189***)
Team give-and-take balance (β = 0.292***)
Communication behavior mediated these relationships:
Teamwork → Communication → Innovation (β = 0.045, indirect)
Information sharing → Communication → Innovation (β = 0.032, indirect)
Give-and-take → Communication → Innovation (β = 0.099, indirect)
Model fit was excellent (χ²/df = 1.950, RMSEA = 0.041, CFI = 0.981)
The pathway is clear: psychological safety creates conditions for open communication, which enables innovative thinking and implementation.
Hospital Emergency Departments (2022): A randomized trial examining interprofessional familiarity found that increased familiarity between residents and nurses (through stable team assignments) significantly improved psychological safety scores. Teams with consistent membership reported:
Higher psychological safety ratings
Better communication patterns during simulations
More confident collaboration in actual clinical work
Research consistently shows that psychological safety doesn't directly drive performance. Instead, it activates three critical team processes:
Learning Behavior: When people feel psychologically safe, they ask questions, seek feedback, admit mistakes, and share knowledge. This accelerates team learning and problem-solving capability.
Team Efficacy: Psychological safety strengthens team members' shared belief that they can accomplish challenging goals. This confidence translates to persistence, risk-taking, and resourcefulness.
Communication Quality: In psychologically safe teams, members communicate more openly, propose diverse ideas, and engage in constructive conflict. This information diversity improves decision-making.
These processes then produce tangible outcomes: higher performance, faster innovation, better safety records in healthcare, and greater employee engagement.
Edmondson identifies three foundational leadership practices that build psychological safety:
What it means: Help team members understand the real stakes and uncertainties of the work. Be explicit about what you don't know and what challenges exist.
Why it matters: When leaders frame work as a problem to be solved collaboratively rather than as a test of individual competence, team members are more willing to contribute. Explicitly acknowledging uncertainty signals that mistakes and learning are expected.
Practical actions:
Share your own uncertainties and incomplete knowledge
Describe the team's mission in terms of learning and adaptation, not just execution
Acknowledge what could go wrong and what could be learned from failures
What it means: Actively and genuinely ask for diverse perspectives, questions, and concerns. Listen carefully and demonstrate that you value input.
Why it matters: Teams don't develop psychological safety through passive tolerance. Active invitation from leaders signals that speaking up is genuinely valued and expected.
Practical actions:
Ask open-ended questions: "What concerns do you have?" rather than "Any questions?"
Pause after asking questions—silence gives people time to formulate thoughts
Explicitly invite perspectives from quieter team members
Ask for input before making decisions, not after
Demonstrate curiosity rather than defensiveness when challenged
What it means: When someone speaks up—whether with an idea, question, concern, or mistake—respond in ways that reinforce that speaking up was the right choice.
Why it matters: A single punitive response to good-faith input can undermine months of trust-building. Conversely, consistent appreciation and action on input strengthens psychological safety.
Practical actions:
Thank people for raising difficult issues
Ask follow-up questions to show genuine interest
Distinguish between intelligent failures (good decisions that didn't work out) and preventable errors (mistakes from carelessness or ignored warnings)
For intelligent failures: focus on learning and improvements
For preventable errors: address the underlying system or behavior while maintaining respect
Implement viable suggestions visibly, or explain why you decided not to
When you make mistakes, acknowledge them directly and discuss what you learned
Creating psychological safety isn't one-time work. It requires consistent reinforcement. Research on high-performing teams found that:
Action learning programs can measurably increase psychological safety. One study showed that teams participating in structured action learning sessions increased their average psychological safety scores and reduced dispersion (variance) in team members' ratings.
Team stability matters. Healthcare teams with consistent membership develop higher psychological safety. Organizations prone to constant restructuring struggle to build safety because trust doesn't have time to develop.
Leadership styles matter significantly. Servant leadership, supportive leadership, and inclusive leadership all predict higher psychological safety. Conversely, authoritarian, punitive, or dismissive leadership undermines it.
Peer relationships are critical. Psychological safety emerges from how colleagues treat each other, not just from leadership behavior. Organizations must cultivate norms of respect, curiosity, and support across the team.
The evidence is compelling:
Innovation: Teams with psychological safety are significantly more likely to generate novel ideas and implement them successfully. Communication behavior fully mediates this relationship—safety enables the open dialogue necessary for innovation.
Error Detection and Learning: In healthcare, psychologically safe teams identify more problems and learn from them faster, ultimately delivering safer patient care.
Retention: Employees in psychologically safe teams report higher engagement and are more likely to stay with the organization.
Collaboration: Cross-functional teams with psychological safety break down silos and coordinate work more effectively.
Adaptability: When uncertainty is high and rapid learning is essential, psychological safety determines which teams adapt quickly and which freeze.
Edmondson developed the Psychological Safety Index to help leaders assess their teams. Key indicators include:
Team members openly acknowledge and discuss mistakes
People ask for help without feeling inadequate
Difficult or sensitive topics are discussed constructively
Team members feel comfortable expressing themselves authentically
Calculated risks and experimentation are encouraged and supported
It's easy to speak up in this team with ideas, questions, or concerns
Organizations typically measure psychological safety through brief surveys, pulse checks, and observational assessments. Regular measurement—quarterly or bi-annually—helps track progress and identify areas needing attention.
Amy Edmondson's research fundamentally changed how the world understands high-performing teams. For decades, organizations believed that excellence came from hiring the smartest, most talented people and holding them to high standards. Edmondson's work revealed that talent alone is insufficient—even exceptional people underperform in psychologically unsafe teams because fear suppresses their contributions.
The path to high performance isn't more surveillance, harsher accountability, or bigger incentives. It's creating an environment where people feel genuinely safe to contribute their full selves and capabilities to the team's mission.
This is not soft management or avoiding accountability. The highest-performing teams combine unwavering psychological safety with uncompromising performance standards. These teams learn faster, innovate more effectively, and deliver superior results because they've created conditions where human potential can actually flourish.
Organization Learning Labs offers diagnostic assessments and leadership coaching designed to help you build psychological safety at scale. Our research-based approach helps leaders identify current safety levels, understand barriers, and implement practical strategies for creating the conditions where teams thrive.
Carmeli, A., & Gittell, J. H. (2009). High-quality relationships, psychological safety, and learning from failures in work organizations. Journal of Organizational Behavior, 30(6), 709-729.
Edmondson, A. C. (1999). Psychological safety and learning behavior in work teams. Administrative Science Quarterly, 44(2), 350-383.
Edmondson, A. C. (2018). The fearless organization: Creating psychological safety in the workplace for learning, innovation, and growth. Wiley.
Frazier, M. L., Fainshmidt, S., Klinger, R. L., Pezeshkan, A., & Vracheva, V. (2017). Psychological safety: A meta-analytic review and extension. Personnel Psychology, 70(1), 113-165.
Google. (2015). Project Aristotle: Toward a higher purpose and mission in our work. Google re:Work Report.
Kim, S., Lee, H., & Connerton, T. P. (2020). How psychological safety affects team performance: Mediating role of efficacy and learning behavior. Frontiers in Psychology, 11, 1581.
Newman, A., Donohue, R., & Eva, N. (2017). Psychological safety: A systematic review of the literature. Human Resource Management Review, 27(3), 521-535.
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