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May 10, 2003
Better Luck Tomorrow
Immigrants in Europe
From the recent Economist an article on immigrants in Europe. Though the tag lines don't mention it-it is basically about Muslims, little mention of West African Christians or British Sikhs aside from a token sentence here & there. This is partially because of Muslim numbers-but also because they are surely more difficult to assimilate.
Forget asylum-seekers: it's the people inside who count
May 8th 2003
The real issue for European societies is not how to keep new foreigners out but how to integrate the minorities they already have
TWO young men set off with suicide bombs to Tel Aviv. One carries out his deadly mission, the other fails. Embittered Palestinians? No. Both are Muslim Britons, one indeed born in Britain.
Why did they do it? The easy answer is extremism—learned in Britain. Few British Muslims are extreme in their faith; hardly any, however they feel about Palestine, are in favour of terrorism. Yet those two men are not just nasty mavericks. They symbolise a wide-ranging question with no easy answers: can Europe integrate its mainly new, and growing, minorities?
Ask the habitually tolerant Dutch. The most potent phrase in Dutch politics today is normen en waarden, norms and values. Traditional Dutch ones, of course; yet few Dutch people two years ago had ever heard the phrase, or thought about the values. Then came September 11th, and then a politician called Pim Fortuyn. Suddenly the Dutch elite noticed what ordinary citizens had long believed, but not dared to say: that many of their immigrant neighbours did not (or so the average Dutchman felt) share these Dutch values.
It was a moment of truth, not only for the Netherlands but for the whole of northern Europe. At last, not just were the long-term effects of immigration openly on the agenda but it was permissible to be open about them; in particular, to admit that they would not go away again if only the plebs would put aside those racial and other prejudices which the better-educated, suburban-dwelling liberal elite wouldn't dream of sharing. Fortuyn was shot dead a year ago; his party was soon in chaos. But the veil that decency and goodwill had cast over discussion of such questions has been decisively torn away.
The main noise since then has been about asylum-seekers and how to keep them out. But the real issue is the immigrants, and their descendants, who are already inside. Integrate these, and European societies could cope well enough with the relatively few asylum-seekers.
Count in their locally born descendants, and there may be 12m-15m poor-country “immigrants” inside the EU: Turks and Kurds, Arabs, Asians (mostly from India, Pakistan and Sri Lanka), all manner of sub-Saharan Africans, Caribbeans, Latin Americans. Some of these communities are long-established, like the West Indians who were first brought into Britain to meet labour shortages in the 1950s, or the Turks who helped to prolong Germany's Wirtschaftswunder, the economic miracle that began 40-odd years ago. Some are newer, like the Bangladeshis who have poured into Britain within the past 20 years. But all share two things. First, they are communities, mostly distinct in skin-colour, language and religion from the natives, and not just random collections of individuals. And, second, these communities are not integrated into the society around them.
And that is the trap into which most European countries, unwittingly, have fallen. Because natural assimilation has worked in the past, they have sat back to let it do its natural work again.
That was not absurd. Most of Britain's 300,000 Jews are descended from east European immigrants of around 1880-1910. When these arrived, they too were concentrated in poor east London; they too spoke foreign tongues, had their own religion and habits, and were often disliked by the natives, some better-off and long-established Jews included. And officialdom lifted barely a finger to turn them into Britons. That was left to the—often vigorous—efforts of sympathetic, or worried, Jews already in place. Yet by now Britain's Jews (the Hasidim apart) are as assimilated, as British, as any descendants of the Angles or Normans. They did it; why not leave others alone today to do the same?
So it is that Oslo has its “little Karachi”; that to Berliners the Kreuzberg district means Turks; that a Parisian calls Montreuil, just to the east, “the second capital of Mali”; that you can count 20 pupils coming out of a Rotterdam primary school before you spot the first obviously Dutch one.
Yet, until recently, few but specialists asked: what is to be done? Britain's Race Relations Board, set up in 1966, has grappled with the question only to reach, in most cases, the usual answer: teach the natives to be less prejudiced. That is a worthy reply, but only half of one. The other half should have been to ask what solid reasons might lie behind the prejudice, and what could be done about them, not least by the minorities at issue. To ask such things was almost like blaming Jews for anti-Semitism. But the answer to both questions is, quite a lot—some of it just the reverse of what good-willed people have done till now.
Go back to the Dutch. Their society was for centuries built on the “mosaic”, not “melting-pot”, notion of integration: we are Catholics and Protestants (and more), we have each our own churches, schools, even sports clubs. But we live in mutual respect, we're all Dutch. Then in late 2001 they got a shock, symbolised by a magazine poll that asked Muslims their view of the September 11th attacks. A bad thing, said 61%. Fair enough? No: what kind of community is it where 39% do not automatically condemn the murder of 3,000 innocents? Not much of one, said the native Dutch—and “not like us”.
So? One response was gut hostility to at least the Arab incomers: the word Marokkanen, preceded by an obscenity, was soon in public use. Another was to demand still fiercer immigration controls than the already tough ones brought in earlier in 2001. But the thoughtful answer—it was Fortuyn's, rapidly taken up by other parties, right or left—was to think how to make the country's Muslims more like “us”.
In Rotterdam, where the Fortuynists became the largest party on the city council, the resultant coalition made a priority of inburgering, the forming of citizens. Get more immigrant children into kindergarten, make sure they master the language, push them to stay longer at school and get better job skills. And act correspondingly for adults, newly arrived or long resident: encourage or shove them into citizenship courses, show them how ordinary Dutch society works and how it thinks.
Such notions can spring from and lead into racism. But it is hardly an act of hostility to make people improve their social or work skills; it happens to all schoolchildren. And to most of the native Dutch, this was simply a reasonable “when in Rome do as the Romans do”, and a recognition that this acculturation was not happening fast enough, but needed to be pushed.
This approach is now spreading fast. Indeed the Danes, a people very conscious of their immigrants, would say they pioneered it. They elected a Liberal (ie, free-market) government in late 2001, and a new ministry for “immigrants and integration” began not just fiercely shutting the doors but also pushing the integration that the previous government had merely talked about. The emphasis is on jobs: “Work is the key to integration.”
Both sticks and carrots are used. Welfare benefits for all the newly arrived have been cut—for their first seven years!—to well below the rates for most Danes. But they can now work part-time while drawing these. To help the process, the newcomer must sign up to compulsory courses in civics and language and, if need be, compulsory work placements. Fail to comply, and your stingy benefits will become even stingier. But extra money is going into integration, for example, to job counselling for immigrants and to educating foreign women brought in for marriage.
That is the theory, and these are early days. Already problems are plain. The government says what is to be done, but the local authorities have to do it, and don't find that easy. Tighter controls on bringing in a bride are unlikely to drive a young male immigrant into instant marriage with a blue-eyed blonde. Nor will a need for nine years of legal residence, plus other requirements, before he can be naturalised as a Dane help to make him feel like one.
That is the trouble: the clash between the widespread European feeling of “Let's have fewer of these people”, and being more welcoming to those already inside. Norway, which is following Denmark down the compulsory “induction” route, has less anti-immigrant feeling. But a new rule won by its most anti-immigrant (and, at this moment, most popular) party bars accepted asylum-seekers from bringing in family members unless they can support them. That will push some people to work, but it will hardly make them feel they belong—and it is not meant to.
Germany for years exemplified a rather different paradox. It welcomed its “guest-workers” as workers, but no way, least of all by easy naturalisation, did it try to integrate them. The newcomers naturally tended, and cheerfully were left, to stick in their national groups, socialising, shopping and praying with each other, reading their own newspapers—Turkey's Hurriyet has a flourishing German-printed edition —and more recently watching their own satellite-television programmes.
An immigration law was passed last year, aimed, among other things, at integration, with publicly financed courses in German language, history and other citizen-like knowledge. Compulsory courses? That was left unclear, as the law itself still is: for procedural reasons, not content, the Constitutional Court last December struck it down. It may yet be revived.
Britain, in contrast, though endlessly alarmed these days about asylum-seekers, has done startlingly little to integrate the millions of immigrants and their offspring, largely from its ex-empire, that it already has. And until recently, and still very largely, the British line has been to accept the resultant mosaic, cross one's fingers and hope: no compulsion here.
The French notion of integration, in contrast, is strictly that of the melting-pot, with the heat supplied by “republican values”, secularism not least. That noble ideal can produce tortured arguments over the right of Muslim schoolgirls to wear headscarves. But, worse, it led for years to official unreadiness to admit that there was a problem with, specifically, the large Arab and Muslim population, and one requiring active treatment.
Since the September 11th attacks, and amid rising alarm about Muslim terrorists, especially from Algeria, there has been much talk of the need for newcomers to accept French values, but little certainty of how to achieve it. The authorities have long been eager to see Islam “naturalised”, with imams trained in France rather than sent and paid for from abroad. France, a secular state by constitution, cannot finance religion. It has, however, been fairly generous in regularising the status of illegal immigrants: of 140,000 who applied when the left came to power in 1997, 80,000 were accepted. This gives some ammunition to the racist right, but it is surely a step towards integration.
This year has brought one more overt effort that way: the setting-up of a single national Islamic council to act as an interlocutor with the authorities. But will this in fact bring more integration—or less? The new body, which met for the first time on May 3rd, was elected in April by delegates from nearly 1,000 mosques. But are these the authentic voice of the Muslim community? The Archbishop of Paris, not alone, doubts it, arguing that most Muslims do not go to the mosque, and that “you can't reduce the issue of North African immigration”—much the largest—“to one of Islam”. What's certain is that the election gave a large voice to Muslim traditionalists and fundamentalists, and these were soon challenging the government over headscarves (in identity-card photos, this time). If such clashes occur often, the new council could be a factor against integration; and the interior minister's threat to deport imams who challenge republican values, which is not yet a crime in France, is no great way to teach those values.
Spain and Italy, parts of which centuries ago were actually ruled by Muslims from North Africa, are by northern standards surprisingly relaxed about their immigrant descendants. Spaniards are proud of the Christian Reconquista, but also of their Muslim heritage; they hear more about the dozens of Moroccans drowned trying to cross the straits of Gibraltar than about the thousands labouring in Andalusia's horticulture and elsewhere. Italians once had a historic phrase “Mamma, li Turchi!”—the Turks (ie, Muslims) are coming! But they are likelier these days to know a not-so-historic north-Italian joke, and it is not immigrants who are its target:
Q: Why did Sicily win the Nobel peace prize?
Italian governments have often acted to legalise illegal workers: measures in 1990, 1995 and 1998 each gave papers to more than 200,000 people. Though one party in the Berlusconi coalition government is openly anti-immigrant, a fresh offer from that government last summer brought almost 700,000 applications. How many will succeed is unclear, given the slow start to the process and the doubts among Mr Berlusconi's governing partners, who see this as a means not of promoting integration but of sorting out who wants to work and who does not, and excluding the latter. The permits in any case will be valid only for a year, though renewable.
More recently, the home minister offered “dialogue” to Italy's moderate Muslims, aiming to isolate the extremists: a move mostly welcomed by Muslims, although the Archbishop of Turin stirred the pot by saying that the church should offer them the Gospel as well. But to Italians the problem with immigration is not so much one of alien values as of the arrival, with the Balkan immigrants, Muslim or not, of Mafia values. And acculturation is still, as ever, left to work largely by itself.
Citizenship and the vote
Still, political rights must have some integrative value. EU countries already let each other's citizens vote in local elections. Now the EU's economic and social committee is arguing for “civic citizenship”, which would give long-term residents from outside equal local-voting rights—and indeed more valuable ones, such as equal access to education and jobs.
Whatever the method, one thing is sure: Europe needs active integration policies. It cannot just sit around and wait for time to sort things out. That has been tried. It has not brought disaster—but it could.
May 09, 2003
Wits and madness
CLARIFICATIONS (and a bit more)
On re-reading my note on ‘Cultural evolution by group selection’, and the comments people have made on it, I realise that some of my terminology was not clear enough - so I hope the following is useful.
‘Heritability’: in referring to the ‘heritability’ of cultural traits I simply meant the tendency of the ‘offspring’ of a group to share some of the traits of the parent group. I did not mean to imply that the basis for this was genetic. The transmission might be entirely through learning and imitation.
‘Fitness’: biologists use different definitions of fitness for different purposes. In my note I was thinking primarily of the relative fitness of one cultural trait compared with another, as measured by their relative numbers of ‘offspring’. I assumed, but did not make this clear, that the relative fitness does not vary according to the frequency of the different traits in the population. So, for example, if the trait of polygamous marriage has a fitness advantage compared with the trait of monogamous marriage, then it has much the same relative advantage whether the trait of polygamy is rare or common. This seems a reasonable assumption for most cultural traits, but I should have made it explicit, because it does affect my argument about the likely fitness effect of any particular trait.
‘Mutation’: by the mutation of a cultural trait I simply mean a variation in the trait, which in turn may be inherited by descendent groups. It need not have a genetic basis. Cultural change during the lifespan of a society is very common, so the ‘mutation rate’ for cultural traits, as thus defined, must be high, and is likely to be an important factor in cultural evolution. I have thought about this a bit more since writing my note. Suppose there are two traits, A and B. Assume that there is a constant rate of mutation from A to B and also a constant rate of mutation from B to A. The rates may be the same, or they may be different. In the absence of selection, the proportions of A and B in the population will be in equilibrium when they are inversely as the mutation rates between the two types. E.g., if the mutation rate from A to B is 30%, while the mutation rate from B to A is 20%, they will be in equilibrium when A is 40% of the population and B is 60%. As I mentioned in my note, the mutation rate might well be high enough to swamp the effects of selection in favour of a trait while it is still rare. However, it did not occur to me that in a sense high mutation rates could actually be favourable to selection. Selection of a new variant would initially be a slow process, because the selective advantage applies only to the small proportion of the population who already possess it. But the mutation rate might bring the proportion of that variant in the population up relatively quickly to a significant level. Selection would then ‘take over’, since it would have, so to speak, more material to work on. Selection (in combination with mutation pressure) might therefore be more important than I thought at first.
But don’t get too excited - as I also mentioned in my note, the rate of increase
Dienekes has been looking for just the right way to define 'race' in an on-going series of posts over at his blog. I know people have a lot of uncertainty with this topic, so I would recommend leaving comments, concerns and questions for him if you have them.
The new PBS series "Race - The Power of an Illusion" motivated him into searching for a new clean and precise way of communicating the biological phenomenon, and determining when and how it should (and shouldn't) be applied.
Is Race for Real? The arguments against the reality of race are based on (a) an extreme view of what the race concept actually meant to most people historically, (b) a misrepresentation of modern scientific facts, (c) social consequences of the race concept, which have nothing to do with its biological reality. I plan to write a series of blog entries on the arguments presented in the PBS Series.
I have not personally seen the program, b/c I don't own a TV (yeah, yeah. Now I'm that guy... I really have nothing against TV, I just don't happen to presently own one), but looking through their website it's clear to me that their message is much more related in substance to American politics than it is to biology.
Dienekes posts so far:
May 06, 2003
ALTRUISM AND GROUP SELECTION
I didn’t intend to comment at length on this subject just yet, but there is evidently some disagreement on the meaning of ‘group selection’, and it may help if I say what I mean by it myself. Sorry, it’s another long one!
A quick disclaimer: nothing in this note is concerned with group selection of cultural traits. It deals only with plain old-fashioned genes. For ‘cultural evolution’ see my earlier note.
Some of this behaviour may simply be accidental, an imperfection of nature.
Historically, biologists in the generations after Darwin attempted to resolve the problem by arguing that among social animals altruistic behaviour would be beneficial to the group in which they lived, and that this group benefit might offset the individual disadvantage. Darwin himself said a few words along these lines. But nobody worked through the details of the process. Then in the early 1960s a British biologist called Wynne-Edwards wrote a long book arguing that many common animal behaviours, such as territoriality, could be explained by group advantage. Wynne-Edwards did not use much mathematics, but he did at least set out the details of the process explicitly for the first time. The problem was that the process he described was absurd, and the biological community turned strongly against group selection (see G. C. Williams, ‘Adaptation and Natural Selection’, 1964).
This left altruistic behaviour to be explained in some other way. Often the paradox can be resolved by showing that the behaviour is not altruistic at all. For example, why kill a defeated rival if in doing so you risk injury? More subtly, altruism might be ‘reciprocal’ and mutually beneficial, if individuals interact frequently enough to exchange benefits. But not every example can be dismissed as ‘disguised selfishness’. The problem is how to explain behaviour which involves a net fitness cost C to the performer, while conferring a net benefit B (in aggregate greater than C), on one or more other individuals. On the face of it, any gene which promotes such behaviour, without conferring any other benefit on its possessor, should be eliminated by natural selection. If all the other individuals in the population possessed the same gene, there would be no immediate problem, because they would collectively receive the greater benefit B. But there is still the problem of explaining how such a gene could have spread in the first place. And even if it did, one would expect selfish variants to emerge, which would receive the benefit without paying the cost.
We must therefore assume that there is a mixed population of ‘altruists’ and
Nevertheless, ‘chance’ would sometimes produce a concentration of altruists
If not chance, what? The most obvious answer is that, in many species, genetic relatives are likely to live near each other. They do not even have to be close relatives in the usual sense - as Hamilton pointed out, in any group, if it is isolated from immigration, genetic relatedness will build up by inbreeding. (It is an empirical matter whether most groups are isolated enough for this to happen.) Hamilton also pointed out that there could be reasons other than genetic relatedness for altruists to associate together - they might recognise fellow altruists as such, or they might settle together because the genes for altruism have some other effect on habitat preference. Sober and Wilson, in ‘Unto Others’, have stressed that altruists may congregate together because everybody, including altruists, wants to be near an altruist. This is a good point, and in a spirit of friendliness (altruism?) towards group-selectionists, I offer the following simple model, which so far as I know is new. Animals live in squares on a chessboard, with at most one animal to each square (some squares are empty). Each animal may therefore have up to eight immediate neighbours. The animals follow two simple rules: if they have three or more altruists as immediate neighbours, they stay where they are; if they do not, they move to a randomly chosen empty square. It is easy to see that some patterns of settlement will be stable under these rules - e.g. a block of four or more altruists in a square or rectangle - while others are not. Altruists will tend to clump together far more than would be expected by ‘chance’. This is of course a fantasy. I doubt if animals often behave like this. Perhaps more important, if altruists tend to associate together they will also tend to interbreed (assuming sexual reproduction), so the model quickly collapses into one of genetic relatedness again.
A large part of the debate is therefore purely semantic. Should a benefit conferred on relatives be described as ‘group selection’? Sober and Wilson and their own ‘groupies’ are probably the only biologists who think it should. There is of course no absolute right and wrong about a semantic issue, but historically this process is not what was originally meant by group selection, and in long-established usage it is known as ‘kin selection’. (Hamilton, in a conciliatory spirit, once suggested calling it ‘kin group selection’.) What decides the issue for me is that the term ‘group selection’ has a proven capacity for causing confusion and woolly thinking, and it should be avoided if at all possible. I would certainly confine it to cases involving (mainly) non-relatives, but even then the various models are so different that I do not think a rag-bag term like ‘group selection’ serves any useful purpose.
Languages, genes & migrations
Nick Wade has an article titled World's Farmers Sowed Languages as Well as Seeds. The following summations near the end capture my view:
May 04, 2003
Rational thinking on immigration
A recent study by the Department of Immigration in Australia confirms the Borjas effect and proposes a solution to it. Note also the reference to the US's ability to absorb immigration which is relevant to the discussion I had with zizka in comments on a previous posting:
CULTURAL EVOLUTION BY GROUP SELECTION
This continues the discussion in my note of 24 April. It’s a long one, so take a deep breath (as the rock star said to the groupie).
First, a couple of preliminaries.
(b) For the purposes of a blog, one must omit all the nuances and elaborations that would be necessary in a published book or article. Also, part of the aim is to provoke debate. However, I will not deliberately say anything that I don’t think is broadly correct.
I finished my last note by saying ‘I do not believe that cultural traits have been produced by any process closely resembling natural selection’. The present note expands on this.
First, there are two distinct ways in which cultural traits might, in principle, evolve by a process resembling natural selection. One way is roughly as follows: social groups (populations, societies, etc.) possess cultural traits; these social groups reproduce and undergo selection; and their cultural traits evolve as a by-product of this process. The second possible way is that the cultural traits themselves ‘reproduce’ and undergo selection directly. The implications of these two processes are radically different, and they must not be confused. Unfortunately they often are.
The present note is only concerned with the first process, which I call ‘cultural evolution by group selection’. The second process (an example of which is Richard Dawkins’s ‘memes’) is more plausible, though not without difficulties of its own. I will return to this in another note.
To evaluate the first process, it would be helpful to have a clear and concise account, by a believer in it, of how it is supposed to work. Alas, I haven’t found any. However, the following, from Hayek’s ‘Law, Legislation and Liberty’ (vol. 1, 1973, pp. 17-19), gives the gist of the doctrine: ‘Mind...is the result of man having developed in society and having acquired those habits and practices that increased the chances of persistence of the group in which he lived...The cultural heritage into which man is born consists of a complex of practices or rules of conduct which have prevailed because they made a group of men successful but which were not adopted because it was known they would bring about desired effects...such rules come to be observed because in fact they give the group in which they are practised superior strength, and not because this effect is known to those who are guided by them.’ In support of these assertions Hayek cites the (now-discredited) work of Wynne-Edwards on group selection among animals, and the classic work of A. M. Carr-Saunders on human demographic evolution: ‘Men and groups of men are naturally selected on account of the customs they practise just as they are selected on account of their mental and physical characters. Those groups practising the most advantageous customs will have an advantage in the constant struggle between adjacent groups over those that practise less advantageous customs’ (Carr-Saunders, ‘The Population Problem: A Study in Human Evolution’ (1922), p.223.)
Unfortunately the advocates of this kind of group selection never seem to bite the bullet and follow through the details of the process. So I will do it for them! In order for the process to allow evolution by natural selection, it must have the following elements:
1. Groups must have ‘reproduction’, i.e. groups must produce other groups.
2. Groups must have ‘heredity’ of cultural traits, i.e. descendent groups must have traits resembling those of their ‘parents’.
3. There must also be some variation in inherited traits. Crudely, the offspring must resemble their parents, but not be identical to them.
4. If the process is to be closely analogous to natural selection, the production of variant traits must be a blind, undirected process.
5. There must be variance in reproductive success. Some groups must have more ‘offspring’ than others, or some 'offspring' must survive better than others, or both. Evolution could in theory proceed entirely by differential reproduction, but obviously if there were ‘reproduction’ without ‘extinction’ the number of groups would increase indefinitely. Since this does not appear to be the case in human history, there must be group ‘deaths’ as well as ‘births’.
6. Variance in reproductive success must be based in part on heritable traits. There will of course also be a random component in reproductive success, but this should not significantly influence the direction of evolution (except maybe in Sewall Wright’s ‘shifting balance’ theory, which incidentally has recently been given a thorough trashing: see ‘Evolution’, vol. 52, 1997).
7. If evolution is to be cumulative, the offspring must themselves have offspring, and so on. As Dawkins has emphasised in his ‘Blind Watchmaker’, the important thing about natural selection is its ability to produce complex adaptations, and this requires iterative, cumulative selection over many generations.
The most obvious objection to this scenario as an explanation of cultural evolution is that societies simply don’t reproduce or die in the way required for the process to work. Or at any rate, if they do, the event is so rare in relation to the amount of cultural change, and the number of cultural traits to be accounted for, that it cannot be a major factor in their evolution. I think this objection is broadly correct, but it is necessary to examine some processes that might be considered sufficiently close to group ‘reproduction’ to invalidate the
Colonisation: by this I mean not just imperial conquest, but the settlement of populations to form new societies, displacing or overwhelming any existing inhabitants, and bringing with them most of the cultural traits of their society of origin. Examples include the British and French settlements in North America, the British settlement of Australia and New Zealand, and the Polynesian settlements in the Pacific islands. Colonisation in this sense is a comparatively rare process, because it requires either that the areas colonised are uninhabited, or that the colonisers have an overwhelming technological superiority. As a basis for cultural evolution, its main limitation is that it is usually a ‘one-off’ event: once a colonial society has been formed, it does not usually create further colonies of its own. It therefore does not lead to cumulative adaptation.
Growth and expansion: some populations grow and expand their territory at the expense of others: for example, the boundaries between Germans and Slavs in Eastern Europe have shifted backwards and forwards over the last 1500 years. Some advocates of group selection treat expansion as analogous to ‘reproduction’; for example, in the book ‘Unto Others’ Sober and Wilson cite the expansion of the Nuer at the expense of the Dinka in Sudan as their prize example of group selection in action. But as with colonisation, growth and expansion by itself does not lead to cumulative adaptation.
Spreading and splitting: if, however, populations expand and then split into distinct groups, some of which themselves expand and split, and so on, we do get an iterative process. This possibility had occurred to me, but an email comment has persuaded me that I should take it more seriously. The ‘spread-and-split’ scenario is similar enough to the reproduction of individual organisms to be plausible as a basis for group selection of cultural traits. There is also little doubt that the process has sometimes occurred in human history; for example, the spread of the Indo-Europeans in Europe, and the Bantu in Africa, have probably involved repeated expansion and splitting. My main reservation is about the frequency and importance of the process. I will come back to this shortly.
The frequency of ‘reproduction’ is not the only problem. For evolution of culture to occur by group selection, it is necessary that variance in reproductive success should be based in part on heritable cultural traits. But it is not clear that this is usually the case. For example, the formation of colonies by Britain was due to a combination of circumstances, most of which are not inherited by its ‘offspring’. The Australians and New Zealanders show no tendency to form colonies of their own, unless you count Hollywood. In the case of the Indo-Europeans and the Bantu, they probably had the accidental advantage of technology (such as iron weapons) which was not possessed by the populations they displaced. And even when the ‘reproduction’ of a society is based on some cultural practice or belief, there is no guarantee that this will persist long enough to be passed on to a third ‘generation’. One of the commonest phenomena of history is that tough nomadic peoples conquer their sedentary
Returning to the problem of frequency, in principle one should set up an explicit population genetics model to explore this. I won’t do this because:
My gut feeling is that group selection will be too slow and too weak to be a major factor. However, I can’t expect people to share my gut feelings, so I will at least make a gesture towards quantifying the relevant parameters:
1. I assume that the number of distinct cultural units (‘societies’) in the world at any one time is around 2,000. This is rather more than the number recognised in ethnographic databases, but these are not complete.
2. For simplicity, I assume that the number of ‘societies’ has been roughly constant since soon after the emergence of Homo Sapiens Sapiens about 100,000 years ago. Obviously this isn’t strictly true - for example, the number of societies will have increased when HSS entered the Americas - but I don’t think variations in the number materially affect the outcome, they just complicate the model.
3. I assume that to count as a distinct unit a society must exist for at least 10 human generations (about 300 years). The average ‘lifetime’ of a society as a distinct unit is more difficult to estimate, but from historical and archaeological data I suggest that an average duration of 1,000 years is reasonable. Admittedly, primitive societies may have a fluid sub-structure, splitting and recombining sub-groups repeatedly over a shorter time-scale than this, but the offset is that these sub-groups are culturally very similar to each other.
4. From the assumption that the total number of societies is roughly constant over time, it follows that there must be one ‘birth’ for each ‘death’: each society must on average produce one ‘offspring’ before it ‘dies’. To maintain the steady state, around 2,000 societies will ‘die’ and 2,000 be ‘born’ around the world in any 1,000 year period.
5. There will be some variance in ‘reproductive success’. Although the average number of offspring is 1, some societies will have none, and others will have more. I suggest a range of about 0-5 ‘offspring’, in approximately a Poisson distribution, with the mode and median both at 0, the mean at 1, and the variance also approximately 1.
6. This modest variance in reproductive success gives some scope for selection, but only a part of the variance, probably less than half, will be based on heritable cultural traits.
7. The fitness effect of any particular cultural trait will usually be relatively small. I assume that there are at least 100 cultural traits (analogous to genetic loci) to be accounted for (this is probably a gross underestimate), and that each of these exists in at least two variant forms (analogous to alleles). The most favourable variant (allele) would not usually have a fitness advantage of more than 10 percent.
If these assumptions are in the right ballpark, group selection of cultural traits must be a weak force. Suppose first that a new cultural variant appears as a ‘mutation’ in one society out of the total ‘population’ of 2,000. The mutation may well go extinct by chance fluctuation before it gets a chance to spread. However, suppose that by a combination of good luck and selective advantage it manages to reach a frequency of 1 percent of the population (i.e. 20 societies). It will then be reasonably safe against chance extinction, and will gradually increase in frequency. But with an advantage of only 10 percent, this will initially be a very slow process: from 1 percent of the population to 1.1 percent, from 1.1 percent to 1.21 percent and so on. The process will gradually accelerate by the ‘compound interest’ effect, but when the ‘allele’ has become relatively common, the rate of increase will be damped down again, because the allele will be competing against itself as well as the less favoured variants. I haven’t done a precise calculation, but I reckon that it would take about 50 ‘generations’ for a new mutation to spread to half the ‘population’. But with a ‘generation’ length of 1,000 years, that is about half the entire lifespan of Homo Sapiens Sapiens since its origin! More important, any new mutation that has appeared in the last 20,000 years - the part of human history we are mainly interested in - would still be at a very low frequency.
It may of course be said that some cultural traits might have a greater selective advantage than 10 percent, and would therefore spread more rapidly. But given the limited reproductive variance, only a small proportion of the 100 or more traits could be in this position, and all the other traits that happened to be linked with these highly advantageous alleles would be carried along as ‘hitch-hikers’, regardless of their fitness effects. In the absence of anything resembling sexual reproduction there would be no easy way of getting rid of undesirable variants by counter-selection (see Maynard Smith, ‘Evolution of Sex’).
I have not discussed the ‘mutation rate’ for cultural traits, but I would guess that it would be orders of magnitude higher than for genetic mutations. It might well be high enough for mutation pressure to swamp the effects of selection. (The point to note here is that the probability of mutation to a particular allele applies to all the members of the population who do not already possess it, whereas a selective advantage applies only to those members of the population who do possess it, which is initially a small proportion. For example a mutation rate of 1 percent applying to 99 percent of the whole population would have more effect than a selective advantage of 20 percent applying to the remaining 1 percent.)
I also haven’t discussed ‘sideways’ transmission of cultural traits from one society to another, e.g. by imitation, but on plausible assumptions this would also tend to swamp the effects of group selection.