“I think we can discern religion’s origins in superstition, which grew out of an overactive adoption of the intentional stance,” he says. “This is a mammalian feature that we share with, say, dogs. If your dog hears the thud of snow falling off the roof and jumps up and barks, the dog is in effect asking, ‘Who’s there?’ not, ‘What’s that?’ The dog is assuming there’s an agent causing the thud. It might be a dangerous agent. The assumption is that when something surprising, unexpected, puzzling happens, treat it as an agent until you learn otherwise. That’s the intentional stance. It’s instinctive.”
The intentional stance is appropriate for self-protection, Dennett explains, and “it’s on a hair trigger. You can’t afford to wait around. You want to have a lot of false positive, a lot of false alarms [...]”
He continues: “Now, the dog just goes back to sleep after a minute. But we, because we have language, we mull it over in our heads and pretty soon we’ve conjured up a hallucinated agent, say, a little forest god or a talking tree or an elf or something ghostly that made that noise. Generally, those are just harmless little quirks that we soon forget. But every now and then, one comes along that has a little bit more staying power. It’s sort of unforgettable. And so it grows. And we share it with a neighbor. And the neighbor says, ‘What do you mean, a talking tree? There’s no talking trees.’ And you say, ‘I could have sworn that tree was talking.’ Pretty soon, the whole village is talking about the talking tree.
Dennett tells a similar “agentification” story: