Why Humans Have Such Big Brains (No, it's not Because of our Intelligence)

So why do we humans have such big brains? According to the NYU neuroscientist Nikolay Kukushkin, it’s because of language. In wanting to talk to one another, Kukushkin argues in his new book, One Hand Clapping, we need to be able to think more coherently than other species. Thus our uniquely big brains. Language itself emerged from our increasingly social lifestyle, Kukushkin explains, which developed after our mammalian ancestors spent 150 million years hiding from dinosaurs in what he calls the "nocturnal bottleneck." And what good have our big brains done us? That, according to Kukushkin, is a trickier question. It’s certainly made us more social, even collective, in our politics and culture. But it also seems to have divided us from one another, fostering as much misery and violence as harmony. Indeed, Kukushkin suggests that we've always been "grumpy"—even back when we lived in caves. The difference now is that we have the internet to advertise our grumpiness. More seriously, though, we're the first species to actually care about our global impact—and that's something worth celebrating, even in our seemingly apocalyptic age.

* Big brains evolved for language, not intelligence - Humans developed large brains specifically to handle the cognitive demands of communication and social coordination, not because we're inherently "smarter" than other species.

* Dinosaurs accidentally created human society - Our mammalian ancestors spent 150 million years hiding from dinosaurs in a "nocturnal bottleneck." When dinosaurs died out, primates moved into daylight and trees, exposing them to predators and forcing them into larger social groups for protection.

* The mind-body divide is imaginary - Kukushkin argues that consciousness isn't a special, separate phenomenon but simply part of the natural world—like discarded notions of human exceptionalism or "vital force" in living beings.

* Collectivism may be more "natural" than individualism - Most human societies throughout history have been collectivist; highly individualistic societies like modern America may be the evolutionary outlier requiring explanation.

* We're the first species that cares about global impact - While humans have always been "grumpy" and prone to conflict, we're unique in actually caring about our planetary-scale effects—giving us potential to change course unlike previous species that nearly destroyed Earth.

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