Jack Bennett was a genetically-engineered Human. He was the unofficial leader of a group of genetically-engineered Humans who lived with him under psychiatric care by Dr. Karen Loews. Jack's parents took him, as a child, to undergo an illegal procedure called accelerated critical neural pathway formation which dramatically increased his intelligence beyond what Humans would call genius level. Jack also had superior physical abilities, such as enhanced agility. However, the procedure also turned Jack into a violent, anti-social, aggressive man who went on to have serious problems fitting in to normal society. (DS9: "Statistical Probalities").