andrewducker: (Default)
andrewducker ([personal profile] andrewducker) wrote2012-03-06 11:00 am
  • Add Memory
  • Share This Entry
Entry tags:

Interesting Links for 06-03-2012

Flat | Top-Level Comments Only

[identity profile] steer.livejournal.com 2012-03-08 10:47 am (UTC)(link)
OK -- let's briefly think about the Flynn effect. One central claim necessary before your argument is that evolution is not currently increasing our intelligence. Before you can claim that evolution cannot increase our intelligence you must certainly be sure that this is not currently happening. If evolution was currently increasing our intelligence then let's think about this on an evolution timescale. Let's imagine an increase which would make "average" into "genius" -- say a 50 IQ point increase. On an evolutionary timescale let's say it will take 50,000 years (which is still actually pretty fast in mammalian evolution terms without selective breeding). So we should be looking for an 0.1 point increase every hundred years. Now, can you really say that you're sure this isn't happening? The Flynn effect (whatever it is) is certainly much larger than this. So before you begin your essay on "why evolution cannot increase our intelligence" you must first show it is not doing so. You really cannot -- if there were an underlying evolutionary change on an evolutionary timescale it would be so small it would be absolutely swamped by the astoundingly rapid changes in human IQ.

Now, that red squirrel. The guy who wrote the essay "no simple changes to an animal could possibly make it more hippity-hoppity eat-ity-nutity than a red squirrel because otherwise nature would have evolved the red squirrel to be better" is looking pretty dumb now. Nature had evolved something much better for that ecological niche, it had just done it elsewhere. It turns out that there was a pretty similar animal which was much better at doing the things that red squirrels do but nature had not evolved it. Why not? Because evolution is not optimising what you think it is. It is not in the business of building the perfect creature to occupy a niche efficiently (despite what discovery channel documentaries say). Only a moderate knowledge of biology will find you huge numbers of examples of invasive species which turn out to be much better in the niche than the invasive species. Take home message: what on earth makes you think evolution is good for optimising "smarts"?

Besides, an increase in intelligence by 10 times being completely fitness neutral is about as likely as flipping a coin 10 times and it landing on edge each time

Why -- what is your evidence for this? And remember, fitness here is evolutionary fitness, not fitness for being smart, not fitness for earing money, not fitness for qualifying for Harvard. Do you have any evidence whatsoever that more intelligent people have more children? Unless that huge intelligence increase actually results in more propensity to succesfully rear children to breeding age it's not increasing evolutionary fitness. It may increase a lot of other types of fitness.

[identity profile] gwern branwen (from livejournal.com) 2012-03-09 04:40 am (UTC)(link)
> One central claim necessary before your argument is that evolution is not currently increasing our intelligence.

That's not necessary at all. The argument is simple: any increase to intelligence will have one of a few properties, or else evolution would already have increased it.

Intelligence could be increasing... as long as the increases had one of the properties.

> The Flynn effect (whatever it is) is certainly much larger than this. So before you begin your essay on "why evolution cannot increase our intelligence" you must first show it is not doing so. You really cannot -- if there were an underlying evolutionary change on an evolutionary timescale it would be so small it would be absolutely swamped by the astoundingly rapid changes in human IQ.

Already addressed Flynn. So your whole objection comes down to 'there might be some process operating now', which is just an argument from ignorance?

> Why -- what is your evidence for this? And remember, fitness here is evolutionary fitness, not fitness for being smart, not fitness for earing money, not fitness for qualifying for Harvard. Do you have any evidence whatsoever that more intelligent people have more children?

I don't. All my evidence points strongly in the other direction - exactly consistent with what I just said, about the fitness neutrality being extremely unlikely, and increases either being fit or unfit. If merely somewhat smart people *already* suffer big fitness penalties as evidenced by low fertility, then that makes it even *less* likely that being 10x smarter would be exactly fitness neutral!

Re:

[identity profile] steer.livejournal.com 2012-03-09 09:17 am (UTC)(link)
If evolution is already increasing intelligence then your argument becomes, there may well be simple ways to increase intelligence with small changes and evolution is currently finding them. As the true situation is that we do not know, the only possible argument is "we cannot possibly tell from evolution if there are simple ways to increase intelligence because we do not know if evolution is currently increasing or decreasing it."

I do not think we are going to agree on the other matter of the fitness neutrality of intelligence.
Flat | Top-Level Comments Only