person going to get ice cream from the fridge
Your split decision to grab ice cream from the fridge may have been programmed deep inside you. Tomi Um

Here’s a mind-bending question: Are you reading this because you definitely chose to or because you were destined to?

Philosophers have pondered free will’s existence for millennia, and neuroscientists began to consider whether humans go about their lives of their own accord in the 1960s. But it wasn’t until a pivotal 1983 study that anyone had any hard evidence in either direction; researchers asked participants to consciously decide to move a finger prior to raising it and recorded their brain activity with an EEG. Surprisingly, before subjects chose to move, their grey matter lit up, suggesting noggins make determinations before we’re aware of them. Over the years, the finding has been met with scrutiny, as the actual reason for those EEG spikes is still unclear.

Modern investigators like Uri Maoz, a computational neuroscientist at Chapman University, are instead tackling the quandary with data. If a supercomputer knows everything about us (from life goals to favorite ice cream) and every decision we make (including instinctual ones happening since birth) influences the next, then a machine could spit out the most likely choice we’d make in any situation. Moaz and others currently study whether there is any chance you’d pick something totally different from what a supercomputer might predict. But in the case of this article, since you’ve nearly finished, it’s more or less a moot point.

This story appears in the Fall 2020, Mysteries issue of Popular Science.