The argument that the Piraha often come out worse off in trades seems to me a complete certainty, based simply on their inability to differentiate between 5 and 50. Regardless of how they value any particular commodity, if they’re as willing to trade 10 Brazil nuts for a bottle of whiskey as 150 Brazil nuts for the same… they’re getting boned on the trade, pretty clear to me.

I have a theory on how to quantify “superiority”, but I’ll get to that in a second…

The most interesting idea that popped up for me reading the comments here is this:
Some have suggested here that the Piraha’s lack of mathematical ability (amongst other things) is because they sleep only a few hours a night, giving them less time to process the day’s activities and learn from them.
I suggest that it is, in fact, the opposite. Perhaps BECAUSE they have such a limited communication/comprehension system they only REQUIRE a few hours to process their daily input. If this is the case, then way back in their cultural infancy Darwinian Evolution may favour Fred, who wakes at 2am, throws a leg over the nearest available female, does so again at 5am and again at 8am… as opposed to Bill, who gets a solid 8hours and wakes in time for his 8am saunter down procreation boulevard. Given a few thousand years of repetition, Fred and his kin would surely out-reproduce Bill and his clan, thus leaving a Piraha society of short-napping leg-overthrowers… if you know what I mean.
Back to the crux of the proposition… seems decidedly un-Darwinian for any behavior that limits procration time (that doesn’t inhibit procreative proficiency, generally due to mortality concerns) to survive, by definition.
Put more simply, Darwinian theory states that the Piraha’s requirement of only a few hours sleep provides a higher procreation rate than more sleep.

At the risk of harping on, it seems that the vast majority of societies have succeeded by becoming more mentally complex, requiring more sleep to process said complexities, and forming compartmentalized societies to make up for 1/3 of the day that they are out of action (and vulnerable to predators).
The Piraha, as my proposition goes, have gone the other way, sleeping little, requiring less brain maintenance (sleep) and being awake to both avoid predators and procreate.

Jesus, I’m clearly writing too much here… meh.

So, how to quantify “superiority”. I suggest that superiority can be judged by a societies understanding of the world they live in. By understanding the nature of the world a society can better judge how they want to live in it. Anyone disagree with that? To those that do, my example is this:
A society that believes if they do not pray 10 hours a day to the God of Sky Altitude, the sky will fall. The sky clearly will not fall if they don’t do this, therefore they are wasting their time. They may be happy to do this, but a society who understands that the sky will not fall can also choose to act the same way… or not… hence being “superior”.
Extending that idea, societies that understand things such as chemistry and physics can develop technology and weaponry that can threaten their own existence. Is this an advantage over a peaceful simpistic society, maybe not, but I still believe it to be superior. The fact that the former society chooses to use its knowledge to produce a threat to its own existence simply proves it less superior to one that, with the same knowledge, is capable of NOT producing the same threat.

End rant. :)

Opinions vigorously encouraged, in fact, demanded.
Mullin

So what I want to know is why they think they are better.

I dont want to sound condescending or anything, I just dont know how else to express my confusion with this.”

Maybe they are better because they lead full lives without mathematics and reading. How much of what we know and what we can do is just useless clutter?