The culture of a team is how people behave and make decisions.
When confronted with a challenge, how will the group of people approach this challenge? What is their mindset when faced with the challenge? What are deemed acceptable and unacceptable methods to resolving the challenge? If the attempted resolution to the challenge fails, how will people react?
Behaviors and decisions are the result of a mindset and norms within the team. The mindset leads to the decisions which lead to the behavior.
Notably, the culture of a team is not declared. The culture of a team is evaluated by the historical behavior and decisions of the team.
An executive cannot announce the culture. It must be observed in the reality of how the team behaves.
Therefore, the truest measure of culture is how the staff describes how people make decisions and behave. Not what an executive states is the culture.
The culture of a team is truly tested during the most difficult of times. When things are getting hard, they look to the leaders for examples of what to do. If their leaders react to difficult times by running around with their hair on fire, yelling, and moving erratically, then the team will follow that behavior. If leaders work calmly and steadily, the team will follow that behavior.
The character of a leader is most apparent during difficult times. When everything is running smoothly, everyone is able to be perceived as an easygoing or good leader.