Google studied its internal teams in hopes of building more successful teams. They found the greatest influence on performance was psychological safety.
The Google Study on Effective Teams
In an effort they called “Project Aristotle,” Google invested two years studying over 100 groups, determined to discover how to build a perfect team. Their findings are reflected in the project name: it was Aristotle who said, “the whole is greater than the sum of its parts.”
The research team defined “effectiveness” using a qualitative and quantitative 4-prong approach including:
Executive evaluation
Team lead evaluation
Team member evaluation
Sales performance
Google then examined team characteristics for emerging themes. They studied team size, seniority of members, intro- and extroversion, individual performance, whether a team hierarchy emerged, and whether or not members socialized outside the group. They found no data supporting their hypothesis that individual intelligence translated into group intelligence or collective IQ. None of their initial focus areas yielded the data they were looking for.
The common factor they did discover among effective teams had little to do with who they were as individuals but had everything to do with how they treated one another. The more successful teams developed positive unwritten rules or group norms. They developed team cultures where risk-taking was encouraged. Effective teams created a turn-taking habit where team members spoke roughly in the same proportion. Members of effective teams also demonstrated high “social sensitivity” or picking up on the cues of others.
This implies that positive norms can uplift a group, but what you might find surprising is that high performance alone does not uplift the group as a whole. A collection of high-performing individuals lacking safety norms will not transform into a more effective team.
Psychological Safety Defined
According to their study, “psychological safety refers to an individual’s perception of the consequences of taking an interpersonal risk or a belief that a team is safe for risk-taking in the face of being seen as ignorant, incompetent, negative, or disruptive.”
Put another way, on a team where psychological safety is the norm, members feel free to contribute without fear of condescension. Members pick up on the cues of others, inviting voices that haven’t been heard or connecting at an emotional level, acknowledging dynamics that might get in the way of full participation.
Think back to the work teams you have participated in. You have likely been on both kinds – teams with little sensitivity and teams where being upset or left out was noticed. Some teams may seem inefficient to a casual observer, going on tangents or socializing instead of following the agenda to a tee. However, many prefer this type of team over one that is overly committed to results.
Safety is extremely important at work (and there are many more types of safety than just physical and psychological).
Measuring and Building Psychological Safety in Your Workplace
This may have been a surprise to some at Google, but psychological safety is foundational to building trauma-informed spaces. On SAMHSA’s list of Six Key Principles of a Trauma-Informed Approach, safety is number one.
Amy Edmondson is a leading researcher on psychological safety. One simple way she offers to test a team for safety norms is to see how strongly they agree or disagree with the following seven statements:
If you make a mistake on this team, it is often held against you.
Members of this team are able to bring up problems and tough issues.
People on this team sometimes reject others for being different.
It is safe to take a risk on this team.
It is difficult to ask other members of this team for help.
No one on this team would deliberately act in a way that undermines my efforts.
Working with members of this team, my unique skills and talents are valued and utilized.
Try this with your team. How strong is the sense of safety among team members?
In her TEDx talk, Edmondson offers three simple things individuals can do to foster team psychological safety:
Frame the work as a learning problem, not an execution problem.
Acknowledge your own fallibility.
Model curiosity and ask lots of questions.
Outcomes-based teamwork should be balanced with process-focused results. As a leader, help your teams see their work as discovery rather than arrival. It’s okay not to understand or mistakenly take the team on a departure of ideas if you thought would be helpful. Asking the right questions is often more valuable than having the right answers, often because there are many right answers.
Final Thoughts: Why You Should Prioritize Psychological Safety
Psychological safety isn't just a buzzword—it's a proven strategy for building more effective teams and fostering long-term success. By prioritizing safety, you empower your team members to take risks, innovate, and collaborate more deeply, creating a culture that thrives on trust and mutual respect.
Google’s research underscores that the most impactful teams are those where members feel seen, heard, and valued. This aligns with trauma-informed principles, highlighting the universal need for safety in all environments, whether you're leading a team, a classroom, or a community initiative. Building psychological safety takes intention, but the benefits are profound: increased retention, heightened creativity, and greater team cohesion.
As a leader, you have the power to make your workplace a space where people don’t just survive but genuinely thrive. Begin by assessing your team's sense of safety and making adjustments that invite trust, vulnerability, and collaboration. When you invest in these practices, the return isn’t just in outcomes but in creating a workplace where individuals and ideas flourish together.
Read more about Why Safety is Important in a Trauma-Informed Approach or download the Safety Plan from our website to take the first step toward building resilience and psychological safety on your team.
For more on Google’s research on teams, read the New York Times article “What Google Learned From Its Quest to Build the Perfect Team.”