Hi Bones,
Actually Adam had to have been created with a nature to sin because he did sin. So that was in his nature to disobey God's command to not eat of the fruit of the tree of knowledge of good and evil. He could eat everything else to his hearts content. But he wanted what God said he couldn't have.
I don't believe Adam wanted the fruit from the forbidden tree I believe he wanted to be with Eve no matter what. Therefore he ate from the tree because I don't think he trusted God to have a solution to this problem of Eve having eaten from the tree. Things might have been much different if he had talked to God about what Eve had done before he ate the fruit.