Editor's pick: Our ancestors may not have been tripping
I was very interested by Alison George's description of cave art symbols used throughout the ancient world (12 November, p 36). But the description of archaeologist David Lewis-Williams's work gives the impression that hallucinations, perhaps part of shamanic rituals, are caused by drugs and migraines.
That is true, but many archaeologists, including Lewis-Williams, state that throughout the world there are many other ways to create shamanistic hallucinations, such as drumming, singing, rhythmic dancing, fasting, meditating, fatigue and hypnagogia (a transitional state to and from sleep). The signs seen in the first stage of the hallucinatory state are very similar, no matter what method is used to achieve that state.
In 1992 I visited members of the Mentawi tribe, still living traditionally on Siberut Island off Indonesia. One evening I saw three shamans conduct their ritual by drumming, singing and rhythmic dancing, which induced a hallucinatory trance that caused them to collapse on the floor.
Culture is not sacred when it oppresses
I am disappointed that researcher Ryan Brown seeks “only to understand” the “honour” aspect of southern US culture, “not change it” (12 November, p 32). He acknowledges that it leads to oppression of women and violence against them.
While I agree that heavy-handed attempts at cultural change based on unreplicated results would be bad, I maintain that where breaches of human rights are endemic to a culture, then those aspects of the culture deserve no more preservation than a disease would – though members of the culture must be sensitively engaged and empowered by those working towards change. Brown notes that “These are my people”. Is he “honour” bound to this culture?
Culture is not sacred when it oppresses
Your article on “honour cultures” was interesting, but could have given more history. The Icelandic sagas, to take just one example, give details of just such a system, operating with its own laws and without a regular state.
First class post
Geo-engineering terrifies me. Technology with planet-wide consequences tied to international politics?
Scott Wahlstrom to Matthew Watson's call for tests of controversial geoengineering methods (p 20)
Unexpected origins of sign languages
Your correspondent bemoans the impending loss of Al-Sayyid Bedouin Sign Language (ABSL) (Letters, 5 November) and accuses Hebrew speakers of lacking respect for “languages and cultures under threat”. Israeli Sign Language (ISL) has no more to do with Hebrew than British Sign Language has to do with… British.
It was developed from German Sign Language, which was taken to Jerusalem in the 1930s. It is the main means of communication for deaf Jews, Arabs, Druze and Bedouins in Israel. If you only sign ABSL, you are confined to one small village for the rest of your life. If you sign ISL, a whole new set of opportunities opens up in education, employment and social relationships.
No one is trying to stop people signing in the village language but it is difficult to see what else the authorities should do other than offer them the same services available to deaf people elsewhere in Israel.
Unexpected origins of sign languages
Shira Rubin observes that Al-Sayyid Bedouin Sign Language achieving the capability to communicate broadly “without complex grammar is largely a mystery” (8 October, p 36). In the 1960s I worked for a parachuting training school: we flew with no door on the aircraft. Wind noise prevented speech. We quickly developed a sign language that was quite complex, conveying details of altitude, air speed, direction and what action to take to compensate for a non-optimal exit from the plane. Needs must…
Some roots and branches of 3D printing
Two readers pointed out that back in 1974, 快猫短视频 columnist Daedalus proposed 3D printing by laser beam polymerisation within a liquid resin – rather than accreting layers as in modern 3D printing (Letters, 12 November). Something similar has actually been done by Satoshi Kawata and colleagues at Osaka University, Japan. Their masterpiece, created in 2001, was a complex sculpture of a prancing bull – the size of a red blood cell (18 August 2001, p 7).
Rather than using two laser beams as Daedalus proposed, they used one pulsed beam. They depended on the fact that in two-photon reactions both must hit the molecule simultaneously, which will only happen at the centre of the focused spot.
Some roots and branches of 3D printing
As long ago as 1989 I was involved in the first wave of 3D printing; but the trumpeting of the recent second wave, which started after some patents expired, perplexes me. I hear that sales of home 3D printers are in decline, as people discover how non-automatic it really is.
But economic forecasters keep predicting exponential growth and markets into the billions. Only for the wealthiest 1 per cent, I think. The value of 3D-printed sculpture is even harder to see than the mass market for customised prosthetics.
Population size is only part of the story
It is certainly true that a drastic cut in the human population could benefit the rest of nature, but Perry Bebbington overlooks some elephants in the room (Letters, 22 October). We are not only part of a damaging species but probably all have relatively well-off Western lifestyles – while the median global income is a few pounds per person per day.
Compare the impact of our lifestyles in terms of diet, cash crops, transport, waste, housing plus water and mineral uses with (say) a Malawian subsistence farmer, and we don't look too good. If human numbers are to fall naturally, the death rate must exceed the birth rate. It is easy to think this ought to apply to other people; accepting our own entry in the obituary column is a little less popular.
Language, nature, nurture and change
Marek Kohn quotes linguist Noam Chomsky concluding: language “is not properly regarded as a system of communication… It is a system for expressing thought” (5 November, p 42). This is the key to resolving the two opposing ideas concerning the evolutionary source of human language: does it spring from nature or nurture?
The 17th-century philosopher John Locke was also clear that the primary role of language is to keep order in the human mind and to be the engine of free will.
Charles Darwin in The Descent of Man, however, proposed that language evolved as an instinctual means of communication “through natural and sexual selection”. He was arguably the originator of the idea of heritable, mutable “memes”, declaring that “the survival of certain favoured words in the struggle for existence is natural selection”.
As Alun Anderson observes, reviewing Tom Wolfe's book about linguists The Kingdom of Speech, none of this explains “how language comes to mean something” (12 November, p 44).
Humans are the only animal that can create a virtual reality in the theatre of the mind, and that can deny the evidence of the senses. Language is the antithesis of instinct. The idea that our thoughts are instinctive is parent to the dangerous idea that culture is innate.
Language, nature, nurture and change
Kohn implicitly poses the question of whether science is or can be politically neutral. There can be no doubt that neutrality is untenable. Science concerns the pursuit of knowledge, which naturally means new knowledge and new information.
Such new information could theoretically be kept isolated from the rest of humanity as some sort of sterile museum exhibit that we could all admire while refusing to change any aspect of our existence. But the history of humanity makes clear that this never has been the case, and probably never will be. Consider the early use of fire for cooking (5 November, p 36).
The work of every scientist can lead to new and possibly (though not necessarily) improved ways of leading our lives: change. Like it or not, change and opposition to change are what politics is all about. It is a cop-out for scientists to claim that they are the seekers of new ideas, but it is the job of politicians to decide what to do with their results.
To provide new information in any expectation other than that it could potentially be applied to the nature of society flies against the universal experience of the last few millennia of human history.
The standard of proof to put value on a life
Discussing the price of a life, Shannon Fischer mentions the case of Victor Nealon (22 October, p 28). His conviction was quashed in 2013 because DNA on a victim's underwear was shown not to be his, but he has not been compensated for the 17 years he spent in prison.
Fischer wrote: “The evidence bar is so high that many receive no compensation at all.” It is worse than that. A claimant for compensation now has to prove beyond reasonable doubt that they did not commit the crime. Nealon could not do this. It is virtually impossible to do so.
The barrister Helena Kennedy said when the law was changed by the then secretary of state Chris Grayling that “to ask people to prove their innocence beyond reasonable doubt is an affront to our system of law.” We are, of course, thankful that the government has achieved its objective of saving money.
The standard of proof to put value on a life
The article left out one method of valuing a life: the purely capitalist principle that a thing is worth only what somebody is willing to pay for it. On that basis, my life is worthless, having reached that point where I'm too old to sell my body for sex, yet too young to sell it for science.