I am Incognito, a mad scientist who studies the bloodline abilities of specific clans. My research has led me to a small village which hosts a powerful family called the uchiha clan. These individuals possess a power called the sharringan, which manifests in the eyes and gives them a range of abilities. This power firsts manifests when in a time when the person is under extreme duress. It is linked to the y chromosome, which allows for only males to access this ability and prevents females from gaining access to it.
My mentor, Orochimaru, tried to gain this ability himself by implanting the eyes of various sharringan users into his own body, or by stealing the bodies of male users who had activated it. However, he was a moron, and ultimately failed in his attempts. I have opted for a simpler method. By taking sperm of uchiha males, I can use them to create an army of uchiha specimens all loyal to me. After securing these genetic samples through....various means, they would be frozen in vials and placed into liquid nitrogen tanks for long term storage. I can then use my own samples into eggs by halving the number of chromosomes from 46 to 23. In-vitro fertilization would then occur, implanting the uchiha material with my own to create children from both lineages.
After these children are born, I would place them in situations that would cause them physical and mental anguish in order to activate the power. However, all my attempts have met with failure. Those who don't meet the expectations are liquidated. No matter how many times the samples are taken or the trials are conducted, no son of mine can activate this power. This doesn't make sense, as I have all the proper genetic information available to me and have followed the steps carefully. I have even used eggs from other "donors" in place of my own, and met with no success.
How can I explain the reason as to why my method is failing?