This indigenous society in Papua New Guinea hates playing.

A small agricultural group known as the Baining in Papua New Guinea is infamous among anthropologists for having eradicated the desire to play from its culture—the Baining do not engage in festivals, games, or religious ceremonies. Researchers such as Gregory Bateson studied the group as early as the 1920s but found it painfully boring. An excellent article at Psychology Today discusses the more recent findings of Cornell professor Jane Fajans:

According to Fajans, the Baining eschew everything that they see as “natural” and value activities and products that come from “work,” which they view as the opposite of play. Work, to them, is effort expended to overcome or resist the natural. To behave naturally is to them tantamount to behaving as an animal. The Baining say, “We are human because we work.” The tasks that make them human, in their view, are those of turning natural products (plants, animals, and babies) into human products (crops, livestock, and civilized human beings) through effortful work (cultivation, domestication, and disciplined childrearing).

The Baining believe, quite correctly, that play is the natural activity of children, and precisely for that reason they do what they can to discourage or prevent it. They refer to children’s play as “splashing in the mud,” an activity of pigs, not appropriate for humans. They do not allow infants to crawl and explore on their own. When one tries to do so an adult picks it up and restrains it.  Beyond infancy, children are encouraged or coerced to spend their days working and are often punished—sometimes by such harsh means as shoving the child’s hand into the fire—for playing. On those occasions when Fajans did get an adult to talk about his or her childhood, the narrative was typically about the challenge of embracing work and overcoming the shameful desire to play. Part of the reason the Baining are reluctant to talk about themselves, apparently, derives from their strong sense of shame about their natural drives and desires.

Some have long suggested that play defines humanity, but according to the Baining, it is work that distinguishes our species. This highlights an important cultural difference, one which is probably more conditional than geographic: As subsistence farmers, like early Americans, the Baining produce what is necessary to survive and little more. Play may be the foundation of our culture today, but in a more utilitarian lifestyle, it's an unaffordable excess. The Baining take Puritanism to a new extreme, where work is not the means to salvation but an end in itself.