Why Cooperation Might Have Shrunk Our Brains

It’s good thing, too! Collective intelligence FTW

Clive Thompson


Two robotic characters from Portal 2, examining an orange and blue portal
Portal 2

Back in 2010, the game designer Matt Wood was working on a sequel to the hit title Portal, when he ran into a really interesting problem:

The awesome power of two brains working as one.

And that, as it turns out, may be related to the mystery of why our human brains have been shrinking for thousands of years.

Let’s unpack this!

Released in 2007, the original Portal was a devilishly clever puzzle game.

You were given a gun that could shoot a portal into any two surfaces, and they’d be connected: Shoot a portal into the wall next to you, one on a remote wall, and you could jump through the nearby portal to emerge far away. In effect, it let you teleport around the room. Your goal was to escape each room by placing the portals in such clever locations that you avoided obstacles and foes while reaching an exit.

The puzzles got harder and harder; I actually never made it to the end. <shrugs> But millions of people are cleverer than I, and man, they loved the game. It sold over four million copies.

In 2007, Wood was tasked with creating the sequel, Portal 2.

This time, his team decided to mix things up by making it a “co-op” game: You’d play alongside a friend, so there’d be two people trying to escape the room, with two portal guns, helping each other.

Wood and his team figured they’d need to make the puzzles harder to solve, so they crafted a bunch of fiendish levels they figured would be pretty brutal. Then they gave Portal 2 to playtesters. He worried they’d made the puzzles too hard; maybe the game would be frustrating?

Nope. Quite the opposite: The teams of two players fairly ripped through the levels, as if they were no big deal.

As Wood explained to me in an email, he’d totally misjudged things. When it came to solving puzzles, he’d expected a team of two people to be twice as good as one person. But two people collaborating were exponentially smarter than one person alone. The two players would often, Wood said, keep an audio channel open as they played the level, and would brainstorm…



Clive Thompson

I write 2X a week on tech, science, culture — and how those collide. Writer at NYT mag/Wired; author, “Coders”. @clive@saturation.social clive@clivethompson.net