The editors gave the last line of this episode to Wentworth as she arrived on Extinction Island. For some reason, she told everyone there that Lauren has an immunity idol. There have been a lot of fans online wondering why the show’s editors put that in. Even though I think some Survivor fans cross over with people who believe the moon landing was a hoax, I do have to admit that it was an odd choice for a last line. Since the editors know who eventually wins, I wouldn’t be surprised if Wentworth’s words will bite Lauren down the road.

Mostly, though, I was reminded of the early episode when Lauren first told Wentworth about her idol. Because in terms of Survivor gameplay, there was almost no benefit for Lauren to do that. The admission just slipped out during a bonding moment. Lauren liked and respected Wentworth, and she wanted Wentworth to feel the same about her, because in the real world these are the building blocks of trust networks.

Despite the way that Survivor (at least originally) marketed itself as going back to primal nature for the people involved, in at least one way it’s probably extremely not like the environment of ancient humans. Ancient humans likely made real pacts with each other. Not flimsy one-day pacts, but until-you-die pacts. Most humans seem wired to trust their allies, because it has so often been a successful survival strategy. Humans create bonds of trust stronger than most other species (especially species not living in hive-like collectives, such as bees and ants), and this has been a significant part of our ability to populate every continent on the planet.

This is also why betrayals among humans sting so badly and can be so fascinating for us to watch. If chimpanzees made and watched Survivor, they might be relatively unmoved when one player betrayed another for personal gain, because that’s much more common among chimps. If opportunities come along for higher rank, better food, or more mates, then many chimps don’t hesitate very long about taking them from an ostensible ally. (Bonobos do seem to form more loyal bonds than chimps, though, which might be a sign that humans are more related to them.)

In fact, many humans take so much trust for granted that they’re often unaware of it. People give their credit cards to complete strangers in restaurants. They often take change from clerks without counting it. When they ask for directions, they assume strangers will try to give good directions. When a stranger tells them a personal story, unless the details go against what they’ve already learned, they assume the stranger is at least trying to tell the truth. To assume otherwise would be a life of uncomfortable paranoia.

Survivor is built in the opposite direction. It encourages players to break alliances and betray each other. It punishes players who trust each other or form bonds of friendship. In my (admittedly limited) experience, most people have trouble adjusting to this type of environment for long periods of time. That might be a reason why so many Survivor players break down emotionally late in the game, crying about how hard it is to be surrounded by people they can’t trust. Although this often seems overly melodramatic, it might be a relatively normal response. This probably makes it very difficult to train someone for Survivor, because the environment is so different from the real world.