People often transfer their own opinions to their users. If a stakeholder, UXer, developer or designer behaves a certain way, they often believe it is a common way for others to behave. This can result in project members being less receptive, dismissing or ignoring new or contradicting insights. There are 3 things you can do to manage such situations. First, understand where project members are coming from to encourage awareness of the these biases throughout the project. Ask how their beliefs were established? Was it through experience, testing, or second hand knowledge?. Second, recruit a wide variety of people as participants in user research to ensure a variety of different responses. Finally, invite stakeholders to observe the sessions to acquire first hand knowledge about their customers."