According to the University of Wisconsin, the life span of monkeys varies by species. The purple-faced leaf monkey is at the lower end with a life expectancy of about eight years.
Many monkeys, such as the southern red-necked night monkey and the northern gray-necked owl monkey, live for about 20 years. One long-lived monkey, the black-handed spider monkey, has a 48-year life span.
The San Diego Zoo points out that most monkeys spend their lives in social groups. They even travel in "troops" when searching for food. These vary in size dramatically, depending upon the species. "Harmens" are subgroups within a troop. Each consists of one adult male, several full-grown females and their young.