The Center for Creative Leadership defines psychological safety as: “The belief that you won't be punished or humiliated for speaking up with ideas, questions, concerns, or mistakes. ... It's a shared belief held by members of a team that others on the team will not embarrass, reject, or punish you for speaking up.”
When Google People Operations (aka HR) wanted to understand what made a Google Team successful, they spent 2 years investigating and conducted 200+ interviews with their employees. In the end, they identified 5 key aspects of a highly successful team. The first on the list? Psychological safety.
The reason for this is quite simple, our brains are wired to identify any potential threats in our environment and respond by putting up barriers. In a workplace, threats can be anything from a boss ridiculing an employee or even a story from a friend about how HR teams aren't trustworthy. Until our brains have seen evidence that we have nothing to fear, we keep these barriers up. This 'fight or flight' mode is very detrimental to our ability to contribute at work, as it prevents us from being creative or taking chances.
"People think that psychological safety is only related to mental health, but it is not. It's about feeling you can be yourself and that no one is going to judge you. When people feel like an ‘other’ they're not comfortable being themselves and they don’t bring their whole self to work. They bring what they think people want to see." - Marie Roker-Jones, Co-CEO of Esteem & Diversity Consultant