Our unconscious bias draws us to people who are familiar to us. We're drawn to similarities and end up favouring interviewees who are like us, but that's not what the business necessarily needs for the role you're hiring.
When we build a team, we look for compliments, but successful teams do not consist of everyone who is the same. both ability and diversity are required for collective intelligence to reach it's potential. You need team members whose different perspectives add value.
At Signature, we use a simple checklist to ensure when we interview we are focused on the business need. Maybe you could find this useful too?