It happens hundreds of times a day: We press snooze on the alarm clock, we pick a shirt out of the closet, we reach for a beer in the fridge. In each case, we conceive of ourselves as free agents, consciously guiding our bodies in purposeful ways. But what does science have to say about the true source of this experience? In a classic paper published almost 20 years ago, psychologists made a revolutionary proposal: The experience of intentionally willing an action, they suggested, is often nothing more than a post hoc causal inference that our thoughts caused some behavior. The feeling itself, however, plays no causal role in producing that behavior. This could sometimes lead us to think we made a choice when we actually didn’t or think we made a different choice than we actually did. But there’s a mystery here. Suppose, that we observe ourselves (unconsciously) perform some action, like picking out a box of cereal in the grocery store, and then only afterwards come to infer that we did this intentionally. If this is the true sequence of events, how could we be deceived into believing that we had intentionally made our choice before the consequences of this action were observed?
This explanation for how we think of our agency would seem to require supernatural backwards causation, with our experience of conscious will being both a product and an apparent cause of behavior. A recent study explored a radical solution to this puzzle. Perhaps in the very moments that we experience a choice, our minds are rewriting history, fooling us into thinking that this choice—that was actually completed after its consequences were subconsciously perceived—was a choice that we had made all along. Though the precise way in which the mind could do this is still not fully understood, similar phenomena have been documented elsewhere. For example, we see the apparent motion of a dot before seeing that dot reach its destination, and we feel phantom touches moving up our arm before feeling an actual touch further up our arm. Postdictive illusions of this sort are typically explained by noting that there’s a delay in the time it takes information out in the world to reach conscious awareness: Because it lags slightly behind reality, consciousness can anticipate future events that haven’t yet entered awareness, but have been encoded subconsciously, allowing for an illusion in which the experienced future alters the experienced past.