Final answer:
New World primate species, such as tamarins and marmosets, produce twins and exhibit long-term pair bonding of males and females.
Step-by-step explanation:
New World primate species, such as tamarins and marmosets, produce twins and exhibit long-term pair bonding of males and females. These species form cooperative partnerships that last at least one season, where the pair cooperatively raise the young. On the other hand, Old World monkeys do not tend to form monogamous relationships.