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Evolution and human kinship
TREE vol. 4, no. 5, May 1989
Sociobiologyand Social Anthropology EvolutionandHumanKinship remain in their own natal groups where their chances of breeding may be small. Hughes is able to show that by Austin L. Hughes, Oxford Univerinclusive fitness will be maximized if sity Press, 1988. f22.50 (viii+162 individuals concentrate their repropages) ISBN 0 19 505234 X ductive effort on those focal individuals on whom their relatedness One of the central problems for human sociobiology is known in concentrates. Having established the groundanthropological circles as the ‘Nuer work for this new interpretation, paradox’. Nuer households contain Hughes then goes on to consider the many individuals who are not genimplications of this view for human etically related to the head of the social behaviour. Among the topics household; many of these affines are he discusses are the way in which male relatives of the householder’s cliques within human groups are wives and their presence cannot be structured, the political bases of explained, the critics of sociobiology chief-ship, patronage and, perhaps have gleefully noted, in terms of most revealing of all, kinshipdirect genetic relatedness. naming. He shows, for example, that Austin Hughes argues that we the way in which groups split when have all been calculating relatedness they undergo fission or when sides the wrong way around when trying to evaluate the implications of kin are taken in a dispute is often based selection in these cases. Thus, when on ways in which relatedness concentrates on focal offspring. Simitrying to determine how groups should split, we have tended to larly, he argues that certain types of local chief are individuals whose assume that the theory of kin selection predicts that individuals will prekinship networks allow them to fer to remain with their closest genexploit a very large set of relatives who can be used to bolster the etic relatives. Not so, says Hughes, for such logic inevitably gives rise to chief’s own status precisely because lineal descent groups and these dehe and his offspring are a focus for monstrably fail to account for the these relatives’coefficientsof relatedness. actual genetic structure of many human groups. Two other examples are worth Hughes’s solution to this difficulty mentioning because they have wide within anthropology. has been to turn the problem on its implications head. He begins by asking what exOne of the criticisms levelled at actly it is that will be maximized in sociobiology by social anthropolevolutionary terms. The answer, of ogists has been the fact that human course, is the inclusive fitness of kinship terminology often correlates alleles. If we then ask how this fitpoorly with genetic relatedness; inness of alleles will be maximized, the deed, in some societies, individuals answer naturally is by maximizing who refer to each other by close the chances that one’s own offspring kinship terms (e.g. ‘mother’ and and those of one’s relatives will re- ‘son’) may not even be related to produce. Hughes points out that, in each other at the genetic level. working this problem out, we conHughes considers the four classical ventionally determine degrees of re- types of kinship classification (native lationship to the individual nominalspeakers of English may be inly making the decision. But, in fact, terested to know that their kinship calculating inclusive fitness in this terminology follows the Eskimo sysway is only an approximation, as tem, the other three being the has long been recognized. Rather, Hawaiian, Omaha and Crow sysargues Hughes, fitness will be maxitems) and demonstrates that in each mized by concentrating reproductive case, relatedness concentrates in difeffort on those individuals who have ferent places. In particular, the Crow the highest reproductive potential and Omaha systems (which are when devalued by their relatedknown to be mirror images of each ness to the individual in question. other) turn out to differ specifically in Hence, in socially living species in terms of paternity certainty. Hughes which adults may not necessarily be uses modelling to show that average able to breed for themselves early in coefficients of relatedness within the their reproductive life, the key consame notional pedigree are signifisideration may be which members of cantly greater under the Crow system the offspring generation have the than the Omaha system of naming largest share of relatedness concenwhen paternity certainty is zero, and trated on them. Affines, in other vice versa. words, have a genetic stake in their The second example is rather relatives’ offspring and may prefer to ironic in the context of the Nuer throw in their lot with exogamously paradox. In a detailed study of the mated female relatives rather than to structure of an East Tennessee 152
mountain community, the social anthropologist concerned concluded that biological relatedness plays no part in the way people view their relationships to each other because none of the four recognized ‘families’ in this community was a lineal descent group. But, as Hughes so elegantly demonstrates, a reanalysis of the pedigrees in terms of relatedness to the offspring generation reveals a close fit between family membership and relatedness to twelve focal sibships in the age group where reproductive value is at its highest. The problem, as Hughes points out, is that referencing family membership to the offspring generation faces severe problems because the individuals in this set are constantly changing as the generations replace each other. An ancestral generation, in contrast, provides a stable, if only reference point. Inapproximate, deed, elsewhere in the book Hughes shows that the identity of an ancestor becomes purely notional once the coefficient of relationship is less than about one-eighth. At this point, it makes little difference whether or not you include a purely mythical individual (or even the sun, as do the Navajo, for example) as an apical ancestor: average coefficients of relatedness among contemporary individuals turn out to be much the same. This book, then, throws an important new light on our understanding of inclusive fitness theory, as well as on the way we apply sociobiological principles to the study of Man. Its implications will, I suspect, continue to reverberate for some years to come for, even if it turns out to be wrong, the challenge it throws at conventional sociobiological theory is bound to generate important new insights. However, in its declared attempt to bridge the yawning chasm between (socio)biologists and social scientists I fear that it is doomed to failure. Most social scientists of my acquaintance will find the matrix algebra and the statistical analyses all but impenetrable and will therefore be inclined to dismiss Hughes’ efforts as magical gobbledegook of no significant import. This will be a pity. But it marks out more than anything else, perhaps, the gap that continues to separate the two disciplines. All the more disturbing is the fact that this gap seems to be widening rather than contracting as sociobiological theory continues to develop apace and becomes ever more mathematical.
Robin Dun&r DeptofAnthropology, University College London, Gower St,London WOE&ST, UK.
Sociobiologyand Social Anthropology EvolutionandHumanKinship remain in their own natal groups where their chances of breeding may be small. Hughes is able to show that by Austin L. Hughes, Oxford Univerinclusive fitness will be maximized if sity Press, 1988. f22.50 (viii+162 individuals concentrate their repropages) ISBN 0 19 505234 X ductive effort on those focal individuals on whom their relatedness One of the central problems for human sociobiology is known in concentrates. Having established the groundanthropological circles as the ‘Nuer work for this new interpretation, paradox’. Nuer households contain Hughes then goes on to consider the many individuals who are not genimplications of this view for human etically related to the head of the social behaviour. Among the topics household; many of these affines are he discusses are the way in which male relatives of the householder’s cliques within human groups are wives and their presence cannot be structured, the political bases of explained, the critics of sociobiology chief-ship, patronage and, perhaps have gleefully noted, in terms of most revealing of all, kinshipdirect genetic relatedness. naming. He shows, for example, that Austin Hughes argues that we the way in which groups split when have all been calculating relatedness they undergo fission or when sides the wrong way around when trying to evaluate the implications of kin are taken in a dispute is often based selection in these cases. Thus, when on ways in which relatedness concentrates on focal offspring. Simitrying to determine how groups should split, we have tended to larly, he argues that certain types of local chief are individuals whose assume that the theory of kin selection predicts that individuals will prekinship networks allow them to fer to remain with their closest genexploit a very large set of relatives who can be used to bolster the etic relatives. Not so, says Hughes, for such logic inevitably gives rise to chief’s own status precisely because lineal descent groups and these dehe and his offspring are a focus for monstrably fail to account for the these relatives’coefficientsof relatedness. actual genetic structure of many human groups. Two other examples are worth Hughes’s solution to this difficulty mentioning because they have wide within anthropology. has been to turn the problem on its implications head. He begins by asking what exOne of the criticisms levelled at actly it is that will be maximized in sociobiology by social anthropolevolutionary terms. The answer, of ogists has been the fact that human course, is the inclusive fitness of kinship terminology often correlates alleles. If we then ask how this fitpoorly with genetic relatedness; inness of alleles will be maximized, the deed, in some societies, individuals answer naturally is by maximizing who refer to each other by close the chances that one’s own offspring kinship terms (e.g. ‘mother’ and and those of one’s relatives will re- ‘son’) may not even be related to produce. Hughes points out that, in each other at the genetic level. working this problem out, we conHughes considers the four classical ventionally determine degrees of re- types of kinship classification (native lationship to the individual nominalspeakers of English may be inly making the decision. But, in fact, terested to know that their kinship calculating inclusive fitness in this terminology follows the Eskimo sysway is only an approximation, as tem, the other three being the has long been recognized. Rather, Hawaiian, Omaha and Crow sysargues Hughes, fitness will be maxitems) and demonstrates that in each mized by concentrating reproductive case, relatedness concentrates in difeffort on those individuals who have ferent places. In particular, the Crow the highest reproductive potential and Omaha systems (which are when devalued by their relatedknown to be mirror images of each ness to the individual in question. other) turn out to differ specifically in Hence, in socially living species in terms of paternity certainty. Hughes which adults may not necessarily be uses modelling to show that average able to breed for themselves early in coefficients of relatedness within the their reproductive life, the key consame notional pedigree are signifisideration may be which members of cantly greater under the Crow system the offspring generation have the than the Omaha system of naming largest share of relatedness concenwhen paternity certainty is zero, and trated on them. Affines, in other vice versa. words, have a genetic stake in their The second example is rather relatives’ offspring and may prefer to ironic in the context of the Nuer throw in their lot with exogamously paradox. In a detailed study of the mated female relatives rather than to structure of an East Tennessee 152
mountain community, the social anthropologist concerned concluded that biological relatedness plays no part in the way people view their relationships to each other because none of the four recognized ‘families’ in this community was a lineal descent group. But, as Hughes so elegantly demonstrates, a reanalysis of the pedigrees in terms of relatedness to the offspring generation reveals a close fit between family membership and relatedness to twelve focal sibships in the age group where reproductive value is at its highest. The problem, as Hughes points out, is that referencing family membership to the offspring generation faces severe problems because the individuals in this set are constantly changing as the generations replace each other. An ancestral generation, in contrast, provides a stable, if only reference point. Inapproximate, deed, elsewhere in the book Hughes shows that the identity of an ancestor becomes purely notional once the coefficient of relationship is less than about one-eighth. At this point, it makes little difference whether or not you include a purely mythical individual (or even the sun, as do the Navajo, for example) as an apical ancestor: average coefficients of relatedness among contemporary individuals turn out to be much the same. This book, then, throws an important new light on our understanding of inclusive fitness theory, as well as on the way we apply sociobiological principles to the study of Man. Its implications will, I suspect, continue to reverberate for some years to come for, even if it turns out to be wrong, the challenge it throws at conventional sociobiological theory is bound to generate important new insights. However, in its declared attempt to bridge the yawning chasm between (socio)biologists and social scientists I fear that it is doomed to failure. Most social scientists of my acquaintance will find the matrix algebra and the statistical analyses all but impenetrable and will therefore be inclined to dismiss Hughes’ efforts as magical gobbledegook of no significant import. This will be a pity. But it marks out more than anything else, perhaps, the gap that continues to separate the two disciplines. All the more disturbing is the fact that this gap seems to be widening rather than contracting as sociobiological theory continues to develop apace and becomes ever more mathematical.
Robin Dun&r DeptofAnthropology, University College London, Gower St,London WOE&ST, UK.