Free The Age of Empathy by Frans de Waal

traveling species (as most primates are). If my companions are feeding, I’d better do the same,because once they move off, my chance to forage will be gone. The individual who doesn’t stay in tune with what everyone else is doing will lose out like the traveler who doesn’t go to the restroom when the bus has stopped.
    The herd instinct produces weird phenomena. At one zoo, an entire baboon troop gathered on top of their rock, all staring in exactly the same direction. For an entire week, they forgot to eat, mate, or groom. They just kept staring at something in the distance that no one could identify. Local newspapers were carrying pictures of the monkey rock, speculating that perhaps the animals had been frightened by a UFO. But even though this explanation had the unique advantage of combining an account of primate behavior with proof of UFOs, the truth is that no one knew the cause except that the baboons clearly were all of the same mind.
    The power of synchrony can be exploited for good purposes, as when horses were trapped on a piece of dry pasture in the middle of a flooded area in the Netherlands. Twenty horses had already drowned, and there were plenty of attempts to save the others. One of the more radical proposals was for the army to build a pontoon bridge, but before this was tried a far simpler solution came from the local horse riding club. Four brave women on horses mixed with the stranded herd, after which they splashed through a shallow area like pied pipers, drawing the rest with them. The horses walked most of the way, but had to swim a few stretches. In a triumph of applied animal knowledge, the riders reached terra firma followed by a single file of about one hundred horses.
    Movement coordination both reflects and strengthens bonds. Horses that pull a cart together, for example, may become enormously attached. At first they jostle and push and pull against each other, each horse following its own rhythm. But after years of working together, the two horses end up acting like one, fearlessly pulling the cart at breakneck speed through water obstacles during cross-country marathons, complementing each other, and objecting to even the briefest separation as if they have become a single organism. Thesame principle operates among sled dogs. Perhaps the most extreme case was of a husky named Isobel, who after having turned blind still ran along perfectly with the rest based on her ability to smell, hear, and feel them. Occasionally, Isobel ran lead tandem with another husky.
    In Dutch bicycle culture, it’s common to have a passenger on the backseat. So as to follow the rider’s movements, the person in the rear needs to hold on tightly—which is one reason that boys like to offer girls a ride. Bicycles turn not just by steering but also by leaning, so the passenger needs to lean the same way as the rider. A passenger who’d keep sitting up straight would literally be a pain in the behind. On motorcycles, this is even more critical. Their higher speed requires a deeper tilt in turns, and lack of coordination can be disastrous. The passenger is a true partner in the ride, expected to mirror the rider’s every move.
    Sometimes, a mother ape returns to a whimpering youngster who is unable to cross the gap between two trees. The mother first swings her own tree toward the one the youngster is trapped in, and then drapes her body between both trees as a bridge. This goes beyond mere movement coordination: It’s problem-solving. The female is emotionally engaged (mother apes often whimper as soon as they hear their offspring do so), and adds an intelligent evaluation of the other’s distress. Tree-bridging is a daily occurrence in traveling orangutans, in which mothers regularly anticipate their offspring’s needs.
    Even more complex are instances in which one individual takes charge of coordination between two others, as described by Jane Goodall with respect to three wild chimpanzees: a mother, Fifi,