They have not built great relationships in the past
Let them stare at the mirror and tell you what they see. Chances are that they will tell you that they have been through so many casual relationships that they really can’t define or tell you what a real relationship means. Whether what they have engaged in the past was casual or broken, they have not put in so much energy in the past to make a relationship a success.
They are elusive
Whether in discussions or actions that are made to signal they are willing to be a part of a real relationship they will be elusive. They will appear vague about what they really want from a relationship. Truthfully they do not have a clarity about what they want and being elusive about it keeps such commitment at bay.
They have been hurt so many times
This is a red flag. Being hurt makes he/she go easy on being committed and providing anything assuring because really they find it difficult to go through that pain of investing emotions and losing it at the end of the day. They would prefer to play it safe and stay away from something real.
They avoid your family and friends
They see your family or friends as elements that represent commitment and responsibility, something that they are not really ready for. They would avoid meeting people that are really close and intimate with you.