Jeffrey

Jeffrey was the holographic son of Kenneth and Charlene, and brother of Belle.

The Doctor, under the name of Kenneth, created a holodeck program in order to experience what family life was like. Initially, the program was far too ideal to accurately simulate the life of a family. Jeffrey was the model son. He did his homework, got good grades and never fought with his sister. After B'Elanna Torres changed the program to make it more lifelike, Jeffrey began to hang out with two young Klingon boys, Larg and K'Kath. He became more rebellious and wished to be more Klingon, against his father's wishes. The Doctor discovered that Jeffrey had a kut'luch with which he was supposed to hurt an innocent person in order to prepare himself for his future life as a warrior. When Belle, his sister, was dying as a result of an accident, he bonded with his family. The pain was too much for The Doctor, and he discontinued the program. 

Jeffrey