Just today, a stranger came to my door claiming he was here to unclog a bathroom drain. I let him into my house without verifying his identity, and not only did he repair the drain, he also took off his shoes so he wouldn't track mud on my floors. When he was done, I gave him a piece of paper that asked my bank to give him some money. He accepted it without a second glance. At no point did he attempt to take my possessions, and at no point did I attempt the same of him. In fact, neither of us worried that the other would. My wife was also home, but it never occurred to me that he was a sexual rival and I should therefore kill him.
Also today, I passed several strangers on the street without any of them attacking me. I bought food from a grocery store, not at all concerned that it might be unfit for human consumption. I locked my front door, but didn't spare a moment's worry at how easy it would be for someone to smash my window in. Even people driving cars, large murderous instruments that could crush me like a bug, didn't scare me.
Most amazingly, this worked without much overt security. I don't carry a gun for self-defense, nor do I wear body armor. I don't use a home burglar alarm. I don't test my food for poison. I don't even engage in conspicuous displays of physical prowess to intimidate other people I encounter.
It's what we call “trust.” Actually, it's what we call “civilization.”
All complex ecosystems, whether they are biological ecosystems like the ...