Letters archive

Ian Morris is non-committal about the likely outcome of the struggle between the egalitarian and the privileged in this world (18 April, p 28) . Underneath the hierarchical values of agrarian society there was always the egalitarian hunter/gatherer nature. To overcome it the liars, cheats and bullies that ruled over us had to spin many …

I was astonished by the parallels between Morris's historical account and the present political landscape in the US. Democratic-leaning friends are frequently baffled by the fact that many working-class Americans support Republican policies that would seem to be against their own best interests. "Perhaps they don't think of themselves as poor," they joke, "but as …

I would like to suggest reasons for the failure of "trickle-down" economics that Ha-Joon Chang describes (25 April, p 28) . The rich put most of their excess income (which is most of their income) into the stock market and into businesses that are already earning a profit. No jobs are created if two investors …

The survival of the concept of "trickle-down economics", in the face of all the evidence, testifies to the power of vested interests. Herbert Hoover, US Republican president from 1929 to 1933, cut taxes for the wealthy. In 1931, after the 1929 stock market crash, he embarked on major programmes to stimulate the economy, such as …

"I, for one, welcome our new carbon nanotube spider overlords!" @welbournd responds on Twitter to reports of spiders spinning enhanced silk (9 May, p 18)

Your article on Neanderthal chefs spicing up their diet had an intriguing final sentence: "we've never found a Neanderthal pot" (18 April, p 14) . In New Zealand Maoris boil or steam their food without pots, either by placing it in woven flax baskets and immersing these in hot pools, or by wrapping it in …

The Chauvet cave puts a nice minimum age on the domestication of dogs that Pat Shipman describes (14 March, p 26) . In it there are footprints of a teenager with wolf-dog footprints running in parallel. Since these run side-by-side and are not overlapping, it is reasonable to suppose they were simultaneous and thus a …

The discovery that nectar toxins are attractive to bees is not totally surprising (25 April, p 42) . We're all attracted to toxins. Fruit toxins and vegetable toxins are part of the "5 a day" that health authorities recommend. They are a key part of the aromas that our noses have evolved to identify as …

Veronique Greenwood's article on colour vision reminded me of something that has puzzled me for a long time (18 April, p 40) . I take a camera when scuba diving. If I leave the "white balance" set for daylight, then the deeper I go the more the colours recorded by the camera diverge from what …

I have been told that I am red-green deficient yet I cannot detect any number in the right hand panel of your Ishihara test for colour blindness, which apparently I should be able to do. More curious still, I cannot reveal any number by using chromatic vision simulator software. Holmfirth, West Yorkshire, UK

• We now discover that the Ishihara test in question was supplied to us on its side, which may have affected the effect. None of us were able to spot this. Also, the other three readers who wrote to say they could not see the number may have sub-types of red-green colour blindness that produce …

Kamaldeep Bhui's valuable article identifies depression as one of the very few common factors among those expressing extremist sympathies (11 April, p 24) . He is completely correct to debunk the conventional wisdom that religious zeal, social deprivation or political grievances are motives. A UK Security Service report leaked by The Guardian demonstrated no ability …

Curtis Abraham describes the risks of redrawing borders of wildlife reserves (18 April, p 26) and William Laurance the role of roads bringing in poachers (also on p 26) . But simply building a road through a forest effectively divides it into two. So if the whole forest was just big enough to support, say, …

You say that Mount Washington has since 1870 hosted "the world's first mountaintop weather station" (11 April, p 22) . But the Meteorologisches Observatorium Hohenpeißenberg was opened on 1 January 1781 and thus predates the US example by 89 years. Friedberg, Germany

Your report on Google's plan to rank its search results by "facts the web unanimously agrees on" (28 February, p 24) and the subsequent letters (14 March) remind me of a comment by the author and broadcaster Clive James. Interviewed on ABC Radio, he acknowledged that he used the internet extensively. Asked his opinion of …