Psychological safety and performance: is there really a measurable link?

Yes, and the evidence is strong. Google’s multi-year research (Project Aristotle) on the factors that make work groups effective analysed more than 180 internal teams and identified 5 factors that predict performance. Psychological safety is the first and the most important: the other 4 (dependability, structure/clarity, meaning, impact) work fully only when there is a solid foundation of psychological safety.

Other research (Edmondson, Harvard 2018) has linked psychological safety to lower turnover, greater capacity for innovation, a reduction in errors reported in time, and better quality of decisions in complex contexts. In medical and aerospace settings there is also evidence of fewer serious incidents.