The feel of green can make people more resistant to low-level pain, NPR reports. Building on earlier research about the psychological power of money, experts in China conducted a study asking subjects to dip their fingers in water heated to 122 degrees Fahrenheit; those who had counted money ahead of time felt less pain. "We think money works as a substitute for another pain buffer—love," says researcher Xinyue Zhou.
Zhou admits with a laugh that it's sad to think of money as a substitute for companionship: "All substitutes are sad," she says. Even reminding the subjects of cash 10 minutes after the experiment had an affect on them. "They said inexplicably they just felt stronger," says another researcher. "It is surprising. It still surprises me."