Yes, I know very well having three arms is not normal...but is it wrong to have them especially if you were born with it?
Liu JunJie is a 2-month old Chinese boy who
Explanation for the 3rd extra limb?
Dr. Chen Bochang, the chief surgeon, speculates that it can be part of the limbs of a conjoined twin that never developed. He said that the two left arms shared part of their joint capsules, and in order to remove the extra limb, they had to divide the joint capsules. He is uncertain how functionality will be affected with a split joint capsule. [A crash course on shoulder anatomy can be read here.] He adds that this is the world's third known case of this type as a hospital in Houston had also received two similar cases before.
Personally, I see nothing wrong with having an extra limb, especially if it is as well-developed as in this case. I think it is better if the decision to remove it was left to Jie-Jie himself when he reaches an age when he can better decide for himself. For all we know, an extra limb might prove to be more of an advantage than a liability.