A REPLY TO IAIN MCLEAN'S PAPER
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'Tit-for-Tat' and Ethical Computers 35 References Axelrod, R. and Hamilton, W.D. (1980), 'The Evolution of Co-operation', Institute of Public Policy Studies Discussion Paper no. 150, University of Michigan. A&elrod, R. (1980a), 'Effective Choice in the Prisoners' Dilemma', J. Conflict Resolution Axel rod, R. (1980b), 'More Effective Choice in the Prisoners' Di lemma', J. Conf 1 ict Resolution XXIV, 3, pp.379-404. Dawkins, R. (1978), The Selfish Gene, reset ed. (London: Paladin). Gale, J.S. and Eaves, L.J. (1975), Comment on Maynard Smith and Price, Nature CCLIV, pp '463- 4. Lewis, D.K. (1969), Convention (Cambridge, Mass.: Harvard University Press), Mackie, J.L. (1978), 'The Law of the Jungle: Moral Alternatives and Principles of Evolution', Phi losophy LI I I, pp.455-64. McLean, I.S. (1981), 'The Social Contract in Leviathan and the Prisoners' Dilemma Supergame', Political Studies XXIX, 3, pp.339-51. XXIV, 1, pp. 1-20. Maynard Smith, J. and Price, G.R. (1973), 'The Logic of Animal Conflicts', Nature CCXLVI, pp. 15-18. Taylor, M. (1976), Anarchy and Co-operation (London: Wi ley). Turnbul 1, C. (1972), The Mountain People (London: Jonathan Cape). -0-000-0- A REPLY TO IAIN MCLEAN'S PAPER HUGH WARD lain McLean's article is a useful summary of Axelrod's important work on the Prisoners' Dilemma. Although his application of this work to the Hobbesian problem is suggestive, I have severe doubts about the claim that it provides a basis for a solu- tion of this problem. be used to modelthe problem of collective action. In many instances, the game of Chicken, which has different properties from the Prisoners' Dilemma in both its simple and supergame version, is a plausible model for this problem (Taylor and Ward, 1981). There is no a-priori reason why an Axelrod type tournament would suggest that 'nice' strategies were the most successful in Chicken supergames. It would be very interesting to know whether this is the case. The Prisoners' Dilemma is only one of a number of simple game structures which may On the basis of Axelrod's work, lain argues that if one or more players can per- suade the others that at least half of them will play 'nice' strategies conditional cooperation will emerge i n the supergame. The Hobbesian problem will be solved because the 'meta-game' is such that it pays to be nice if enough others are nice. This seems to me to be an extremely tenuous basis on which to claim that a solution of the Hobbesian problem exists. Persuasion would only work as a coordinating device if players were poorly informed about the intentions of others. Why s h o u l d A believe B who i s claiming that at least half the other players intend to be nice when he knows that B is also imperfectly informed? It is often suggested in the games theoretic literature that the most rational thing to to i n a game of uncertainty is to 'play safe', minimising the maximum possible losses you might make (minimax principle). in a Prisoners' Dilemma superqame is universal defection. This is not to suggest that persuasion would never work or chat other plausible devices for solving the coordination problem might not emerge. Tbe-2 is however the problem of who will bear the costs of coordination. Contrary to what lain seems to suggest, it is often plausible that members The minimax strategy
Transcript of A REPLY TO IAIN MCLEAN'S PAPER
'T i t - for-Tat ' and Ethical Computers 35
References Axel rod, R. and Hami l ton, W . D . (1980), 'The E v o l u t i o n o f Co-opera t i on ' , I n s t i t u t e o f P u b l i c P o l i c y S tud ies D iscuss ion Paper no. 150, U n i v e r s i t y o f Mich igan.
A&elrod, R . (1980a), ' E f f e c t i v e Choice i n the P r i s o n e r s ' Di lemma', J . C o n f l i c t R e s o l u t i o n
Axel rod, R . (1980b), 'More E f f e c t i v e Choice i n t h e P r i s o n e r s ' D i lemma', J. Conf 1 i c t R e s o l u t i o n X X I V , 3, pp.379-404.
Dawkins, R . (1978), The S e l f i s h Gene, r e s e t ed. (London: P a l a d i n ) .
Gale, J.S. and Eaves, L.J. (1975), Comment on Maynard Smith and P r i c e , Nature CCLIV, p p '463- 4. Lewis, D.K. (1969), Convent ion (Cambridge, Mass.: Harvard U n i v e r s i t y P r e s s ) ,
Mackie, J.L. (1978), 'The Law o f t h e Jungle: Moral A l t e r n a t i v e s and P r i n c i p l e s o f E v o l u t i o n ' , Phi losophy L I I I , pp.455-64.
McLean, I . S . (1981), 'The S o c i a l Con t rac t i n Lev ia than and t h e P r i s o n e r s ' Dilemma Supergame', P o l i t i c a l S tud ies X X I X , 3 , pp.339-51.
X X I V , 1 , pp. 1-20.
Maynard Smith, J . and P r i c e , G . R . (1973), 'The L o g i c o f Animal C o n f l i c t s ' , Nature CCXLVI, pp. 15-18. T a y l o r , M. (1976), Anarchy and Co-operat ion (London: W i l e y ) .
Turnbul 1 , C . (1972), The Mountain People (London: Jonathan Cape).
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A REPLY TO I A I N MCLEAN'S PAPER HUGH WARD
l a i n McLean's a r t i c l e i s a u s e f u l summary o f A x e l r o d ' s impor tan t work on the P r i s o n e r s ' Dilemma. Al though h i s a p p l i c a t i o n o f t h i s work t o t h e Hobbesian problem i s suggest ive, I have severe doubts about t h e c l a i m t h a t i t p rov ides a b a s i s f o r a s o l u - t i o n o f t h i s problem.
be used t o modelthe problem o f c o l l e c t i v e a c t i o n . I n many instances, t h e game o f Chicken, which has d i f f e r e n t p r o p e r t i e s f rom t h e P r i s o n e r s ' Dilemma i n bo th i t s s imp le and supergame v e r s i o n , i s a p l a u s i b l e model f o r t h i s problem ( T a y l o r and Ward, 1981). There i s no a - p r i o r i reason why an Axe l rod t ype tournament would suggest t h a t ' n i c e ' s t r a t e g i e s were t h e most success fu l i n Chicken supergames. I t would be ve ry i n t e r e s t i n g t o know whether t h i s i s t he case.
The P r i s o n e r s ' Dilemma i s o n l y one o f a number o f s imple game s t r u c t u r e s which may
On the b a s i s of A x e l r o d ' s work, l a i n argues t h a t i f one o r more p l a y e r s can pe r - suade t h e o t h e r s t h a t a t l e a s t h a l f o f them w i l l p l a y ' n i c e ' s t r a t e g i e s c o n d i t i o n a l coopera t i on w i l l emerge i n t h e supergame. The Hobbesian problem w i l l be so lved because t h e 'meta-game' i s such t h a t i t pays t o be n i c e i f enough o t h e r s a r e n i c e . T h i s seems t o me t o be an ex t reme ly tenuous b a s i s on which t o c l a i m t h a t a s o l u t i o n o f t h e Hobbesian problem e x i s t s . Persuasion would o n l y work as a c o o r d i n a t i n g dev i ce i f p l a y e r s were p o o r l y in formed about t h e i n t e n t i o n s o f o t h e r s . Why should A b e l i e v e B who i s c l a i m i n g t h a t a t l e a s t h a l f t h e o t h e r p l a y e r s i n t e n d t o be n i c e when he knows t h a t B i s a l s o i m p e r f e c t l y informed? I t i s o f t e n suggested i n t h e games t h e o r e t i c l i t e r a t u r e t h a t t h e most r a t i o n a l t h i n g t o t o i n a game of u n c e r t a i n t y i s t o ' p l a y s a f e ' , m i n i m i s i n g t h e maximum p o s s i b l e losses you m igh t make (minimax p r i n c i p l e ) . i n a P r i s o n e r s ' Dilemma superqame i s u n i v e r s a l d e f e c t i o n . T h i s i s n o t t o suggest t h a t persuasion would never work o r chat o t h e r p l a u s i b l e dev ices f o r s o l v i n g t h e c o o r d i n a t i o n problem migh t n o t emerge. Tbe-2 i s however t h e problem o f who w i l l bear t h e c o s t s of c o o r d i n a t i o n . Con t ra ry t o what l a i n seems t o suggest, i t i s o f t e n p l a u s i b l e t h a t members
The minimax s t r a t e g y
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o f t h e group would f i n d i t b e n e f i c i a l t o leave t h e persuading t o o the rs . The game o f o r g a n i s i n g coopera t i on may w e l l be a P r i s o n e r s ' Dilemma so t h a t t h i s approach mere ly pushes t h e problem one s tage f u r t h e r back.
Could e v o l u t i o n a r y processes overcome l a c k o f c o o r d i n a t i o n by bypassing c o l l e c t i v e a c t i o n problems i n o r g a n i s i n g c o o r d i n a t i o n ? There a r e w e l l known problems w i t h t h e a p p l i c a t i o n o f arguments f o r t h e e v o l u t i o n o f c o n d i t i o n a l coopera t i on t o human popula- t i o n s . I n p a r t i c u l a r , c u l t u r e seems t o i n t e r v e n e c r u c i a l l y between g e n e t i c s e l e c t i o n and human i n s t i t u t i o n s (Sahl i n s , 1977, p a r t 1 ) . The a n t h r o p o l o g i c a l evidence seems t o suggest t h a t a l t r u i s t i c and c o n d i t i o n a l l y c o o p e r a t i v e behaviour i s more impor tan t among t h e c u l t u r a l l y d e f i n e d k i n group than t h e theo ry o f k i n s e l e c t i o n would lead us t o expect. What seems t o m a t t e r i s whether t h e k i n s h i p system d e f i n e s another as c l o s e r a t h e r than b i o l o g i c a l p r o x i m i t y . A x e l r o d ' s model i s one s tage f u r t h e r away from t h e evidence about s o c i e t i e s which m igh t be seen as good t e s t cases f o r these s o r t s o f theo ry ( S a h l i n s , 1977, p .41) . I t would suggest t h a t c o n d i t i o n a l coopera t i on w i t h a l l o t h e r
p l a y e r s whether g e n e t i c a l l y r e l a t e d o r n o t would tend t o evolve. There would be no g r a d i e n t i n the degree o f coopera t i on as one moved f u r t h e r and f u r t h e r away f rom t h e k i n o f t h e i n d i v i d u a l . But such g r a d i e n t s seem t o t y p i f y c o o p e r a t i v e behaviour i n such s o c i e t i e s as one moves f u r t h e r and f u r t h e r away f rom t h e c u l t u r a l l y d e f i n e d k i n group. To be f a i r t o Axel rod, h i s model was n o t designed t o s tudy such problems. But they do seem impor tant here.
I t h i n k t h a t we should d i s t r u s t any t h e o r e t i c a l a s s e r t i o n , no m a t t e r how w e l l qua- l i f i e d . , t o have so lved t h e problem of c o l l e c t i v e a c t i o n . I t i s p a t e n t l y t h e case t h a t c o l l e c t i v e a c t i o n sometimes takes p l a c e and sometimes f a i l s . The c e n t r a l t h e o r e t i c a l q u e s t i o n i s t o e x p l a i n t h i s f a c t .
References
T a y l o r , M. and Ward, H . (1981), 'Chickens Wahles and Lumpy P u b l i c Goods'. Paper g i v e n a t t h e P o l i t i c a l Studies A s s o c i a t i o n Conference, H u l l U n i v e r s i t y , A p r i l 1981. Fo r th - coming i n P o l i t i c a l S tud ies .
Sah l i ns , M. (1977), The Use and Abuse o f B i o l o g y : An A n t h r o p o l o g i c a l C r i t i q u e o f Socio logy (London: T a v i s t o c k ) .
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ARE LABOUR SELECTORS PREJUDICED AGAINST WOMEN CANDIDATES? D A V I D T . DENVER
I n Volume 1 Number 2 o f P o l i t i c s , E l i z a b e t h V a l l a n c e p rov ides an i n t e r e s t i n g ana ly - s i s o f t h e e l e c t o r a l performance o f women as opposed t o men candidates i n genera l e l e c - t i o n s (Val lance, 1981, pp.27-31). She does t h i s , however, i n t h e c o n t e x t of an a t t a c k upon p a r t y s e l e c t i o n conferences a s s e r t i n g t h a t l o c a l s e l e c t o r s , who a r e predominant ly male, er roneously b e l i e v e women t o be a bad e l e c t o r a l r i s k ar:d consequent ly do n o t s e l e c t them as candidates i n w innab le seats . Yet no d i r e c t evidence i s o f f e r e d (un less the q u o t a t i o n f rom Bernard Shaw counts) t h a t l o c a l s e l e c t o r s do i n f a c t b e l i e v e t h i s . I t i s t r u e t h a t r e l a t i v e l y few women candidates a r e s e l e c t e d b u t t o a s s e r t w i t h o u t e v i - dence t h a t t h i s i s a r e s u l t o f i l l - i n f o r m e d p r e j u d i c e on t h e p a r t o f s e l e c t o r s i s unwarranted. I wish he re t o present some ev idence which suggests t h a t t h e a l l e g e d b i a s o f s e l e c t i o n conferences a g a i n s t women i s something o f a myth, a t l e a s t i n t h e case o f t h e Labour P a r t y . (de legates t o s e l e c t i o n conferences) i n 18 c o n s t i t u e n c i e s - 8 Labour-held, 4 marg ina l and 6 hopeless f rom Labour 's p o i n t o f v iew. The i n t e r v i e w s were conducted between 1976 and 1979.
( i n c l u d i n g sex) and asked whether each was e l e c t o r a l l y advantageous o r disadvantageous
The d a t a a r e d e r i v e d f rom i n t e r v i e w s w i t h 487 Labour s e l e c t o r s
S e l e c t o r s were presented w i t h a l i s t o f s o c i a l c h a r a c t e r i s t i c s o f candidates
