The Boskops.

They were here on the planet contemporaneously with us. They had great big heads and cute little faces. They were smarter than us. How much smarter? Well, it says here that we are Homo Erectus to their Homo Sapiens.

Put your head around that one.

We spend a lot of time here at the Speculist pondering the next stage of human evolution. What if that next stage arrived 10,000 years ago and then mysteriously disappeared?

Or perhaps not so mysteriously. It's possible that:

They were a small population that never really caught on. (Those big heads were not doubt hard to deliver, making fecundity problematic.)

Some catastrophe got the better of them.

They were out-competed, or simply wiped out by smaller-brained contemporaries (i.e., us).

That final possibility is a bit chilling. Neanderthals had bigger brains than we do, too. Were they smarter than us? Were smarter strains of humanity nicer than dumber ones? Nah, it couldn't be that simple. If dumber humans always won out over smarter ones, Homo Erectus would have kicked our Sapien butts. And Erectus was no slouch when it came to the business of survival. They hung in for 1.5 million years -- making them by far the most successful (at least in terms of longevity) strain of humanity. No doubt there were many factors in play that determined which strain of humanity became dominant, including luck.

But please note that not everyone agrees that Boskops were a separate strain of humanity. The consensus view is that they were a few outliers within the Homo Sapiens -- kind of a big brain high water mark:

To be sure, there has been a reduction in the average brain size in South Africa during the last 10,000 years, and there have been parallel reductions in Europe and China -- pretty much everywhere we have decent samples of skeletons, it looks like brains have been shrinking....[It] is hardly a sign that ancient humans had mysterious mental powers -- it is probably a matter of energetic efficiency (brains are expensive), developmental time (brains take a long time to mature) and diet (brains require high protein and fat consumption, less and less available to Holocene populations).

What the -- brains are shrinking? Now ask yourself this question. Which scenario do you prefer: the one where mean old H. Sapiens wiped out the smarter, more peaceful contemporary humans, or the one where we're the small-brained descendants of big-brained, smarter ancestors?

Luke McKinney provides much-needed perspective:

The fundamental flaw, the assumption that a bigger brain automatically means increased intelligence, is more suited to Dr Freud than a modern professor - and embarrassingly crude launching point for a discussion of sophisticated mental processes. A sperm whale brain is 6 kilograms of raw neural matter capable of little more than "swim. eat. repeat", while Albert Einstein's skullbox was actually a smidgen smaller than average.

The point is not the volume of the brain, but the complexity of the wiring. The critical factor is the number of connections between different neurons, massively enhanced in humans by the distinctive folding pattern which increases the surface area of our brains. Animal brains have far fewer folds, down to the lower species which have no folds at all, just clumps of neurons.

Just like the old saying: "It's not the size that counts, it's how you use it to create a massively complicated neural network capable of planning and independent thought".

Yep, that's what I always say. So there probably was no big-brained human species, and if there was they probably weren't all that much smarter than we are.

All of which ought to tell us something. The fact that I can't say exactly what that is has less to do with the size of my brain than how it's folded.

Er, right?