The Capuchin Monkey becomes sexually mature after 4 years of age. They reproduce in the same way all other mammals reproduce, by having sexual intercourse. They are considered year round breeders. The menstrual cycle occurs every 14 to 20 days and they may give birth every two years. They give birth of one baby and the gestation is about 160 days. 
At birth, the infants cling to the front of the mother. After it ages a bit, it clings to the mothers shoulder, on its back. After a period of three months they let go of their mother’s back and begin to walk on their own. However, the mother still helps out, holding the monkey’s tail as it learns how to walk. 
The Tufted Capuchin monkeys are polygamous animals. The alpha males of the monkey's pact get to mate with all of the females of the group, while the other males must wait until he is gone in order to get a chance to reproduce.