TEMPE, AZ—Saying the apes demonstrate an almost unique capacity for minding their own business, a new study released Thursday by primatologists at Arizona State University found that chimpanzees are the only animal besides humans capable of keeping the lid on a friend’s affair. “After observing a range of different species, we found that chimpanzees were the only ones who, upon discovering that their friend had a mistress or just a little action on the side, understood that they should keep their mouth shut and look the other way,” said head researcher Martha Yue, adding that while other animals almost universally blabbed to their friend’s mate as fast as they possibly could, chimpanzees instinctively knew not to run their mouths to anyone in their troop. “MRI scans revealed that chimps’ brain plasticity has developed in such a way that they can act as if they saw absolutely nothing after discovering the illicit couple picking fleas off each other’s shoulders. These same tests revealed that the regions of the chimp brain governing emotion, while not as sophisticated as our own, were nevertheless more than capable of stifling nagging feelings of guilt or complicity for decades, even under direct, anguished interrogation from the victim of the infidelity.” The researchers also speculated, however, that chimpanzees were physiologically similar enough to humans that many would completely let the cat out of the bag after a couple glasses of wine.