It’s very likely these Neanderthals, although able to interbreed with humans, and probably capable of speech, will be on average considerably less intelligent than humans. If I had to guess I would suppose their average adult IQ to be about 70, or -2 SD relative to modern humans. You might wonder how they could have survived for 300k+ years with such modest intelligence, but based on my experiences with 5-10 year old kids I don’t think that a sub-adult level of maximum intelligence precludes the ability to form societies and function as hunter-gatherers. (Apes survive with even less cognitive ability.) I just don’t think that higher developments (e.g., invention of writing) are likely for such a population. What Homo Sapiens accomplished in 50-100k years far outstrips Neanderthal accomplishments over a much longer period of time.

I find this comment very confusing, because why is he comparing what Homo Sapiens have accomplished in 50-100K years to what Neanderthals have accomplished “over a much longer period of time”?  Shouldn’t he be comparing what the two species accomplished at the same time?

All the higher developments Hsu speaks of (i.e. invention of writing) didn’t occur until about 35,000 years after Neanderthals went extinct and even “advances” like agriculture didn’t occur until about 30,000 years after.  If the IQ of our species is judged only by the accomplishments we made at the same time as Neanderthals,  we had no higher developments either.

But Hsu seems to be saying “it’s not when you accomplish something that reflects IQ, but how long it took you to accomplish it.”    Obviously a more intelligent species will be expected to learn, invent and discover things faster than a less intelligent species,  but Homo Sapiens have been around a lot longer than 50-100 K.

I don’t doubt Homo Sapiens are smarter than Neanderthals and that we accomplished more, even contemporaneously, I’m just puzzled by the achievement rate over  50-100 K years being compared to “a much longer period of time”?

Perhaps you could say that anatomically modern humans first appear in the fossil record somewhere between 195 kya and 300 kya, depending on how you define “anatomically modern” and still exist today.  Let’s split the difference and say we’ve been around for 248,000 years.

Meanwhile Neanderthals first appear in the fossil record between 400 kya and 600 kya.  Again, splitting the difference, about 500 kya, but since they vanished 40 Kya, they lasted 460,000 years.

So maybe one could say our species accomplished far more in 248,000 years than Neanderthals accomplished in 460,000 year,  but this doesn’t really tell us much about our differing rates of accomplishment.

What is needed are achievements that Homo Sapiens made that Neanderthals also independently made, but at a later date, so we can compare.

For example, Homo Sapiens started engraving quite a complex geometric pattern” by about 70 kya at Blombos Cave in South Africa.  Meanwhile Neanderthals started carving “abstract, almost geometric shapes” by about 40 kya in Gorham’s Cave in Gibraltar.

So could one argue that Homo Sapiens acquired this skill when our species was just 178,000 years old (248 kya – 70 kya) while Neanderthals didn’t acquire it until their species was 460,000 years old (500 kya – 40 kya)?

It’s tempting to apply the old age ratio method of calculating IQ to claim Neanderthals had an IQ only 39% as high as modern humans (178,000/460,000 = 0.39) but that’s clearly nonsense, and one of the reasons it’s nonsense is it’s not as if we were starting from scratch when we became our species 248,000 years ago, nor were Neanderthals starting from scratch when they became Neanderthals 500,000 years ago.  Both species were building on the accomplishments of ancestral forms.

So perhaps instead of starting the clock at the speciation point, we should start it at the last common ancestor of both species.  Research suggests “the early predecessors of humans diverged from those of Neanderthals between 550,000 and 765,000 years ago — too far back for the common ancestors of both to have been Homo heidelbergensis, as some had posited”.

Let’s split the difference and assume the two species diverged 658 kya, which means it took Homo Sapiens (and our ancestors) 588,000 years to create geometric designs (658 kya – 70 kya), while it took Neanderthals and their ancestors 618,000 years to do the same.  Applying the old ratio IQ method would now suggest their IQ was 85% as high as ours.  A lot more believable than 39%, but possibly still nonsense.

 

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