EX Partner was left for Dead as a new born and Im trying

When my ex was born, his birth mother took him to the Souel South Korea city dump and left him for dead. They believe he survived on his own for nearly a week before he was found at the brink of death. He was nursed back to health and then immediatly adopted and was flown to Seattle Washington. When I met his parents his adopterd mother told me this story like it was nothing right in front of him. She then went on to say he had attachmeny issues as a baby. That when you adopt that mother child bond is not already there so your supposed to hold the baby for a relatively long period of time to creat that bond. She said it was hard to do because he wouldnt just lay there and so she said he had bonding and attachment issues. I have no idea what to call this type of problem he had. But i was trying to find information or books or theories as to how they develop into adults and psychological effects it creats as an adult and on relationships.