Copyright Sociological Research Online, 1998

Paul Marsden (1998) 'The Selectionist Paradigm: More Implications for Sociology'
Sociological Research Online, vol. 3, no. 4, <http://www.socresonline.org.uk/3/4/6.htm l>

Abstract

This paper argues that despite 50 years of empirical research, the phenomenon of social contagion is still poorly understood. Social contagion research has produced an eclectic, largely confused and jumbled body of evidence that lacks any comprehensive organising principle or conceptual framework. Whilst the great majority of this empirical research has identified and confirmed existence of the social contagion phenomenon, results have been undermined because the phenomenon itself has been variously and ambiguously defined and operationalised. This has meant that the potential radical implications of social contagion research findings for an orthodox understanding of the human individual as a rational Cartesian agent, have been largely ignored. It is suggested that the emerging evolutionary paradigm of memetics may provide a novel conceptual framework for understanding and explaining the empirical phenomenon of social contagion, by understanding it as the observable action of selfish memes replicating through a population. The article concludes by proposing a memetic theory of social contagion, and ends with a call for the synthesis of the two bodies to create a comprehensive body of theoretically informed research.

Keywords:

Behavioural Contagion; Coevolution; Emotional Contagion; Evolution; Imitation; Meme; Memetics; Selectionism; Social Contagion; Social Learning

Introduction

1.1

Havingre- established itself in psychology (e.g. Barkow, Tooby and Cosmides 1992), cognitive science (e.g. Dennett 1991), economics (e.g. Hodgson, 1993), anthropology (e.g. Rindos 1985, Durham 1991, Sperber 1996), and epistemology (e.g. Sober 1984, Plotkin 1982), evolutionary thought is again knocking at the door of sociology in the guise of W.G. Runciman's reintroduction of the selectionist paradigm to a sociological audience (Runciman 1998a, see also Runciman 1998b, 1998c).

1.2

The selectionist paradigm conceptualises evolution, descent with modification, as a two step process; the generation and selection of variation are held to be causally independent. More specifically, the capacity for variation is understood to be inherent in the process of replication, whilst the selection of variations is held to be dependent on the environment. More specifically still, the paradigm holds that evolution through selection will necessarily occur given certain conditions:

• Replication rule for behaviour in a game of Chinese Whispers; the rule is replicated each time it is passed on or transmitted.
• Variation Such as when the individual misinterprets or mishears the rule before passing it on.
• Selection Where a set of constraints provides a rationale for selecting variations, such as when the individual knows that only one in-group rule is being passed on, but is unsure whether they heard "wear sneakers" or "bare beakers".

1.3

The paradigmatic example of the power of selectionism is, of course, Darwin's demonstration that species can have the appearance of being 'designed' to 'fit' their environments through nothing more than mechanical iterative loops of this evolutionary process of replication, variation and selection (a href="#Darwin 1859").

1.4

By applying the selectionist paradigm to the organic world, Darwin showed that it was not necessary to invoke miracles or deities to account for design. Rather design could emerge naturalistically from evolution by selection. What was particularly startling about this early application of the selectionist paradigm was that it proceeded quite successfully without any knowledge of a) the mechanics of variation, b) the mechanics of replication (inheritance), or c) the units of replication. In fact, Darwin was able to apply the paradigm whilst knowing a good deal less about the dynamics of the organic world than sociologists currently know about the dynamics of the social world. However, these shortcomings did not prevent Marx from declaring that the paradigm had successfully dealt a "death blow" to teleology and suggest that it was to serve as the basis for his own views (Marx cited in Heyer 1982:15-18). Despite Marx's enthusiasm, the subsequent use of selectionism in sociology has been minimal for a number of reasons that Runciman and others have enumerated and explained elsewhere (Runciman 1998c, van de Berghe 1990).

1.5

After dispelling a number of misconceptions that sociologists might have about the selectionist paradigm, Runciman's article in Sociology argues that the paradigm has a number of important implications for sociology. Critically, Runciman argues that evolution by selection is operating in the social world and by ignoring it, sociologists disregard an important dynamic in the social world. The sociological way of seeing should at the very least take cognisance of the fact that the social world is not "just one damn thing after another, but one damn thing instead of another" (Runciman 1998c, my emphasis).

1.6

As Runciman correctly argues, evolution by selection must be operating in the social world because all the conditions necessary for the evolutionary loop to operate are met. This holds not only for evoked ('genetic') and acquired ('cultural') behaviour, but also imposed ('social') behaviour. Social behaviour, made up of practices (units of reciprocal action), is passed from generation to generation (replication) with variation, and some variations are selected differentially over others. The task of a selectionist sociology, according to Runciman, is to expose the selective environment that results in the persistence of some practices, roles and institutions over others.

1.7

Despite their heuristic provocativeness, the distinctions between evoked, cultural, and social behaviour might ultimately confuse the nested hierarchical character of behaviour and perpetuate the false dichotomy of nature and nurture. Social behaviour can be understood as simply institutionalised cultural behaviour, which in turn is both grounded and framed in genetic processes. Nevertheless, Runciman's main point is good and his evolutionary project for sociology is exciting, if not new.

1.8

This central implication for sociology that evolution by selection is operating in the social world has been most extensively explored by Thomas Burns and Tom Dietz. (Dietz, Burns and Buttel 1990, Burns and Dietz 1992, 1997, Dietz and Burns 1992, but see also Langton 1979). In order to operationalise the paradigm, Burns and Dietz have argued that, just as is the case in the biological world, the social world can be understood as the differential transmission and selective retention of rules and rule systems (see also Cloak 1975, Dawkins 1982). The reciprocal application of these rules leads through habituation to institutionalisation, the emergence of practices and social structure, and allows for a distinct evolutionary sociology (see also Marsden 1998a, Berger and Luckmann 1966). The empirical task of sociology, from this perspective is to audit the replication, variation and critically, the selection of rules employed over time within particular institutions and contexts (Marsden in progress).

1.9

A further implication of selectionism for sociology, only briefly touched upon by Runciman. is the paradigm's potential to provide a conceptual integration between sociology and biology. Matt Ridley's The Origins of Virtue (Ridley 1996) is a provocative and interesting excursus into this potential. Ridley argues that the human capacity for, and tendency to engage in, reciprocity is a product of biological evolution; co-operation is, so to speak, in our genes. Put differently, from the evolutionary perspective, co- operation is not only a cultural phenomenon, it is also an evolved, evoked and particularly human sociobiological disposition. This adaptation, the genetically evolved predisposition to reciprocate, provides sociology with the foundations for an evolutionary explanation of a number of social phenomena including, for example, the importance of reciprocity in social influence (see Cialdini 1988 for a review of this phenomenon).

1.10

This sort of bridge-building, that is, the use of the selectionist paradigm to span the artificial nature/nurture (evoked/acquired/imposed) divide is useful because it lays the foundations for a comprehensive, conceptually integrated understanding of human behaviour. The selectionist paradigm allows for the sociological explanation of social phenomena in terms of evolved non- miraculous processes that are compatible with, but not reducible to, human biology (see Palmer and Donahue 1992 for a development of this view). To further illustrate this bridge-building potential of the selectionist paradigm, an evolutionary theory of imitation will be invoked to explain the peculiar but ubiquitous phenomenon of social contagion.

The Problem of Social Contagion

2.1

The term contagion (ken_tâ_jen) has its roots in the Latin word contagio, and quite literally means "and from touch." Contagion refers to transmission through touch or contact. For over a century, social scientists have been struck by the tendency of certain behaviours, as opposed to diseases, to spread through populations as if they were quite literally contagious e.g. ( Baldwin 1894) Tarde 1903, 1963 and Le Bon 1895 1903. In some circumstances, mere exposure to behaviour appeared to suffice for that behaviour's replication and spread. This is the social contagion phenomenon.

2.2

Since the 1950s, a considerable body of empirical evidence has been amassed confirming both the existence and voracity of social contagion in a number of areas of social life (see Levy and Nail 1993 for a review). Human behaviour, in both local and dispersed collectivities seems to tend towards homogeneity even in the absence of coercion or any identifiable rationale. This peculiar phenomenon is not restricted to behaviour (as usually conceptualised); research has demonstrated how emotions also appear to be contagious (Hatfield, Cacioppo, and Rapson 1993, Doherty 1997). Empirical studies demonstrating emotional contagion have focused on mood (Hsee, Hatfield and Chemtob 1992), anxiety (Behnke et al 1994), fear (Gump and Kulik 1997), appreciation (Freedman and Perlick 1979), stress (Pfefferbaum and Pfefferbaum 1998), and enjoyment (Freedman, et al., 1980).

2.3

Within behavioural contagion research, a number of types of behaviour have been found to spread by contagion. Firstly, the spread of medical symptoms and signs for conditions for which there is no medical basis have been well documented (Kerckoff and Back 1968, Colligan and Murphy 1982, Freedman 1982, Houran and Lange 1996, Showalter 1997, Marsden 1997). Such contagions are known hysterical contagions, or symptoms of 'mass psychogenic illness'.

2.4

A second class of behaviour that sometimes appears to spread through populations by contagion is rule violation. Examples include teenage smoking (Ritter and Holmes 1969, )(, Rowe, et al1992), speeding (Connolly and Aberg 1993), substance abuse (Ennett, et al.,1997), delinquency (Jones 1998), youth sex (Rodgers and Rowe 1993) and criminality (Jones and Jones 1995).

2.5

A third type of contagious behaviour is deliberate self-harm (DSH), of which suicide is the paradigmatic example. (Phillips 1974, Phillips 1980 ,1982, Stack 1987, 1990, Higgins and Range 1996, Gould, et al., 1987, Gould, et al., 1989, Gould 1990, 1996, Marsden 1998b).

2.6

A fourth behavioural contagion is the financial contagion where the infectious behaviour of market dealers results in panics, buying frenzies, and crashes that sweep across both domestic and international exchanges (Orlean 1992, Temzelides 1997, Lux 1998).

2.7

A fifth type of behavioural contagion that has been identified and subjected to extensive research is that of consumer behaviour (Marsden in press). Successful predictive models of fashions and fads that spread like viruses through a population have been successfully developed and are commonly used in forecasting exercises in industry (see Rogers 1995 for a review).

2.8

A sixth type of contagion that has been the focus of sustained research is that of aggressive behaviour which has been shown to spread through both crowds and dispersed collectivities. Extensive research confirming the voracity of this contagion of aggression has not only been of an experimental nature (Bandura, et al., 1963, Wheeler and Caggiula 1966, Wheeler and Levine 1967, Wheeler and Smith 1967, Goethals and Perlstein 1978), but also descriptive (Bandura 1973, Reicher 1984, Lachmann 1996), and correlational (Atkin, et al., 1979, Sheehan 1983, Phillips 1983).

Explaining away the Social Contagion Phenomenon

3.1

Despite the common finding of non-rational clustering in human behaviour, and despite the successful development of contagion models with good predictive power (see Rapoport 1983 for a review), social contagion research is characterised by its unorganised, disparate and incoherent nature. Social contagion research currently lacks any organising principle or conceptual framework to guide and inform its activity (Levy and Nail 1993).

3.2

This chaotic state of affairs is exemplified by the various social scientific definitions that exist for contagion, which range from the ridiculously vague to the plain contradictory. For example, the Penguin Dictionary of Psychology (Reber 1995) defines contagion as the "spread of an activity or a mood through a group", a definition that is barely more useful than the Concise Oxford Dictionary of Sociology's (Marshall 1994) cursory notion of "ideas moving rapidly through a group." Other definitions attempt to define contagion in terms of non- rationality (e.g.Furnham 1983), whilst others stipulate the absence of a perception of intention to influence (e.g. Levy and Nail 1993). Other variations argue that contagion is consequence and subset of disinhibition, and require a prior condition of approach-avoidance conflict for contagion to occur (e.g. Wheeler 1966).

3.3

As would be expected from the inconsistent potpourri of definitions, attempted explanations of the contagion phenomenon are similarly eclectic and incoherent. However, they typically share one common feature; they reject the very hypothesis upon which contagion is based, transmission by mere exposure. Just as we do not choose to be infected with biological contagions, we often behave as if we have little control over the social contagions that infect us. Most explanations, however, eschew this conclusion and are characterised by an attempt to restore a reassuring internal Cartesian (rational, evaluating, choosing) homunculus to its traditional throne in the explanation of human behaviour. In other words, despite the extensive evidence suggesting that under certain circumstances, we automatically and unconsciously imitate those around us, explanations of social contagion have sought to impute Cartesian voluntarism into a process where, for once, it simply isn't required. In this way, accounts of the social contagion (spread by simple exposure) phenomenon have typically attempted to explain away rather than actually explain the phenomenon.

3.4

The line of argument usually taken to explain away the contagion phenomenon is that underlying the superficial appearance of evoked imitation there are far more subtle and complex processes operating (presumably because we are, after all subtle and complex humans). Thus, a number of explanations have involved the suggestion that the spread of homogeneity is a consequence of deliberate, conscious and fully evaluated action in situations usually defined by the uncertainty or ambiguity (e.g. emergent norm theory (Turner 1964), social learning theory (Bandura 1971, 1986). Other theories have suggested that the clustering of behaviour is simply the manifestation of latent homogeneity in 'prior motivations' that antecede, and give rise to collectivities in the first place (e.g. convergence theory (Turner and Killian 1987)). Other such 'prior motivation' type theories include disinhibition theory (Freud 1922 1959, Redl 1949, Wheeler 1966, Ritter and Holmes 1969, Levy and Nail 1993) and deindividuation theory (e.g. Diener 1976, 1979, Festinger, et al., 1952, Zimbardo 1969), where social proof and anonymity are held respectively to engender conscious restraint reduction in individuals.

3.5

Whilst one or another of these explanations may indeed go someway to explaining the social contagion phenomenon (although it is difficult to see how any could reasonably account for emotional or hysterical contagion), a much simpler evolutionary explanation exists. The human organism has an evolved and innate disposition for responding to stimuli for which it has no clear inherited (evoked, acquired or imposed) response by imitating those around it.

The Evolution of Imitation

4.1

One of the fundamental implications of the Modern Synthesis of Darwinism and population genetics is that biological evolution by natural selection operates primarily for the benefit of the units that are replicated, and not for the individual, group or the species. The individual phenotype is understood as a "gene machine" or "gene vehicle", a product of variations having being selectively retained because of the reproductive and survival advantages that they confer on their precious genetic cargo. This is the Selfish Gene Thesis popularised by Dawkins (1976), a position that follows directly from the observation that the evolutionary loop of variation, replication and selection operates independently of any interests and ontogenetically acquired traits of the individual, group or species.

4.2

This gene- centred understanding of the evolution would seem to imply a sort of 'genetic imperialism' where life itself is reduced to, and determined by, the interactions of genes via their phenotypes with their environment. Once we accept the fact of evolution and accept that protobacteria have no social world, then it becomes problematic to explain human behaviour in terms of an independent social world. This is because that all separates us from these, our direct ancestors, is a finite number of iterations of the evolutionary loop of replication, variation and selection. This fact has led some theorists to deny the very existence of a social world at all, or at the most suggest that it be on a genetic "leash" (e.g. Lumsden and Wilson 1981). However, it is not necessary to be such "greedy reductionists" (Dennett 1995) within the evolutionary paradigm since the iterative loop has the power to produce emergent properties (but not miracles) that are dependent on but not reducible to organic evolution. A good case can be made for the proposition that one such emergent property is the human capacity to imitate.

4.3

In the closing chapters of The Selfish Gene, Dawkins, who is often incorrectly accused of genetic reductionism and determinism, suggested that an independent social world has indeed emerged non- miraculously from natural selection, and that this social world is based on the process of imitation. Just as genes satisfy the criteria for evolution by selection so too, he argued, does culture; culture is transmitted (replicated) with variation, and only some variations persist (selection). Humans, according to Dawkins are not only products of genetic evolution, but also cultural or 'memetic' (to rhyme with genetic) evolution. We are vehicles, not only for genes, but also culture.

4.4

Of course, the validity of an evolutionary theory of culture relies not on partial analogies between genes and 'memes', but rather on how culture could emerge non-miraculously from a genetically determined world. A number of theories of a broadly similar nature have been developed to this end (e.g.Dawkins 1982,Rindos 1985, 1986,Dennett 1991, 1995,Barkow et al. 1992, Plotkin 1994). For culture to emerge non-miraculously from a genetically determined world it must be shown that a) the capacity for culture is adaptive for genes, and b) that culture itself does not violate fundamental laws of the natural world. If culture were not adaptive for genes then the capacity for culture would not have come to be selected in the first place, and if the putative emergence of that culture involved violating the processes out of which it emerged, then that culture must be mere chimera.

4.5

Is culture adaptive? Consider for a moment the genes of a creature whose behaviour is fixed at birth. These genes would stand little chance of remaining in the gene-pool of a population were the creature to exist in a non-stable environment. Any significant change in the environment upon which it depended would result in the creature's demise because totally pre-programmed behaviour would preclude the possibility of learning. However, any genetic mutation that allowed for a degree of phenotypic plasticity would be selected, that is, spread through the gene-pool, because it would allow for adaptive post-natal design fixing, thus conferring enhanced survival and replication chances on the genes. In this way, instructions in the central nervous system could be ontologically acquired rather than genetically inherited, through an initial process of trial and error. Faced with a novel stimulus for which there is no evoked response, the creature whose plasticity allowed it to acquire a response would have its survival chances enhanced, allowing the plasticity to be passed on to the next generation and more generally through the gene-pool.

4.6

However individual learning of this kind would be time-consuming and costly. Yet once a creature can learn from its environment, the possibility is raised for learning from that part of that environment defined by the behaviour of others. In this way, a far more effective learning process could non-miraculously emerge; social learning. By copying the functional relations between stimulus and response objectified in the behaviour of those around it, an individual could save costly resources (Boyd and Richerson 1985). This capacity for imitation would be selected because it would further enhance the survival chances of genes, simply because imitation is cheaper than innovation (see Flinn 1997, for a review of evolutionary theories of social learning). The important point to remember in the evolutionary emergence of social learning is that imitation, from a gene's eye view is an adaptive strategy, particularly if learners, as opposed to imitators, can be identified (Boyd and Richerson 1995).

4.7

Imitation as an advanced form of learning appears to be particularly rare in the animal kingdom (Laland 1992, Blackmore forthcoming) and extensive imitation may a uniquely human trait. However, the significance of imitation for sociology lies not in its scarcity in the non-human world and its ubiquity in the human world, but in the fact that its emergence would result in an evolutionary process taking place in a new substrate. Cultural instructions (i-culture in Cloak's terminology) could pass between brains (replication) by being instantiated in behaviour (m- culture), be subject to variation and therefore evolve according to their own selective pressures. In this way, the human organism would become the vehicle for an evolutionary selection process operating in two substrates, the biological and the cultural. Such an evolutionary insight is not new, in fact it is over a century old. The 19th Century sociologists, Gabriel Tarde (Tarde [1903], 1963) and James Baldwin (Baldwin 1894) argued that imitation is a fundamental process upon which the social world is built.

4.8

In the same way that Ridley was able to explain co-operation in the social world in terms of an evolved and largely unique, genetic predisposition to reciprocity, the social contagion phenomenon may be explained by an evolved, non-miraculous human capacity and predisposition to imitate. When responses to a stimulus in a individual's behavioural repertoire are either absent, or conflicting, such a theory might contend that the human organism has an evolved disposition to imitating the behavioural responses of those also exposed to that stimulus. This is an empirical hypothesis requiring no non-natural or supernatural processes that is consistent with the social contagion data and an evolutionary understanding of the human condition and which is open to falsification.

4.9

But is this no more than saying "when in Rome, do as the Romans do," a social conformist rule of thumb that could be just as equally a product of rational deliberation than as an evoked behavioural response? Well, yes but...the evolutionary paradigm requires that emergent processes do not violate the operating principles of the processes upon which they depend. Internal hobgoblins of mind (Cialdini 1988) or homunculi (Dennett 1991) with all sorts of supernatural deliberative powers do quite fragrantly violate these principles. To be sure, it is possible to provide an account of contagion by positing an internal homunculus that has a number of supernatural powers including the ability to perform mental gymnastics in n-dimensions. But if such rational evaluating homunculi or agents exist in the brain, then who is supposed to be evaluating the situation in the 'heads' of the homunculi? Attempting to explain human social behaviour in terms of fully sentient internal agents simply takes one down the road of infinite regress. The alternative is to posit a non-material 'ghost in the machine' which may be endowed with the full set of rational and evaluative powers that typical explanations of contagion require. But how could such a mysterious non- material entity have any effect whatsoever in the material world of behaviour? In other words, to paraphrase (Dennett 1991), how can a phantom both pass through a wall and knock things flying? The answer is it cannot. Rather than get tied up in dualist knots, an evolutionary account of social contagion offers an alternative non- miraculous explanation of the phenomenon in terms of an evolved imitative response.

The Selectionist Paradigm and the Deconstruction of Agency

5.1

By building an understanding of the social world based on non-miraculous evolved processes (e.g. reciprocation, imitation, deception), one radical implication of the selectionist paradigm is that it may go someway to deconstructing the 'irreducible' Cartesian notion agency that continues to permeate sociology. Just as the biological world can be understood as the product of competing selfish genetic instructions, so too can the social world be understood as a product of competing selfish memetic instructions. Evolution will occur in the social world because all the conditions for evolution have been met; replication, variation and selection. And just as genetic evolution proceeds in the exclusive interests of what is replicated, so too might memetic evolution. Whatever other forces are involved, the mechanical iterative evolutionary loop will produce ever more 'fit' cultural instructions, that is, cultural instructions that are good at doing what replicators do, replicate (Allison 1992, 1993, Hirshleifer 1995). This is perhaps what gives culture its increasingly epidemiological character with fashions, fads and crazes sweeping through populations more like virulent viruses than as consequences of rational deliberation and choice (Dawkins 1993, Marsden in press).

5.2

From the selectionist paradigm, the human condition can be characterised as a nexus for evolution occurring in two substrata, the genetic and the memetic. Whilst this co-evolutionary theory (see Durham 1990 for a review) explicitly eschews genetic or biological reductionism and determinism, it comes with an anti-homuncular sting in its tail. In the same way that we do not choose our genes because we are our genes, we do not choose our culture or memes because we are our culture or memes. Culture spreads and evolves not because we, as agents standing miraculously outside the evolutionary process choose it to be true, good or beautiful, but rather because it is adapted to the copying machinery of brains, that is, it is good at getting itself replicated. Just as we do not choose when to yawn or sneeze, we cannot choose in any non-trivial sense what we want to believe. If you doubt this, ask yourself whether you could you really believe that the moon was made out of cheese even if you really, really wanted to. We like to think we are in control, whoever 'we' may be, and indeed we are in control, but only insofar as we are unique biographies of a functional nexus of sets of behaviour.

5.3

From such an evolutionary stance, the problematic concept of the self can be understood as the non-miraculous product of memes instantiated in our brains and objectified in the environment. To use Dennett's evocative phrase, the self may simply be a 'centre of narrative gravity,' a web of discourses and behaviour that are spun around the locus of a particular brain (Dennett 1991). Selves, from this perspective, do not exist outside discourse and behaviour, selves are discourse and behaviour. Memes spin selves like a web, creating narratives that appear to emanate from a single source only because they are replicated by, and adapted to, genetically evolved brains.

5.4

This is the radical and controversial implication of the selectionist paradigm for sociology, that human agency might be usefully deconstructed into sets of instructions instantiated in cultural and biological phenotypes. Whilst such an implication might not be particularly palatable to those who would endow agency with an irreducible Cartesian homunculus, the selectionist paradigm offers sociology a viable alternative framework that can be conceptually integrated with, but not reduced to, our knowledge of the organic world.

References

ALLISON, P. (1992) Cultural relatedness under oblique and horizontal transmission rules. Ethology and Sociobiology, 13, 3: 153-169.

ALLISON, P. (1993) The cultural evolution of beneficent norms. Social Forces, 71, 2: 279-301.

ATKIN, C.K., GREENBERG, B.S., KORZENNY, F., & MCDERMOTT, S. (1979) Selective exposure to televised violence. Journal of Broadcasting, 23, 1: 5- 13.

BALDWIN, J. M. (1894). Imitation: A chapter in the natural history of consciousness. Mind, 3: 25- 55.

BANDURA, A. (1971) Social Learning Theory. N.Y. General Learning Press.

BANDURA, A. (1973) Aggression: A Social Learning Analysis. NJ. Prentice-Hall.

BANDURA, A. (1986) The Selectionist Paradigm and the Deconstruction of Agency Social Foundations of Thought and Action. Engelwood Cliffs, NJ: Prentice-Hall.

BANDURA, A., ROSS, D., and ROSS, S. (1963) Imitations of aggressive film-mediated models. Journal of Abnormal and Social Psychology, 66: 3- 11.

BARKOW, J., COSMIDES, L., and TOOBY, J. (1992) The Adapted Mind: Evolutionary Psychology and the Generation of Culture. NY: Oxford University Press.

BEHNKE, P.R., SAWYER, C.R., & KING, P.E. (1994) Contagion theory and the communication of public speaking state anxiety. Communication Education, 43, 3: 246-251.

BERGER P.L. and LUCKMANN T. (1967) The Social Construction of Reality. Garden City, NY. Doubleday, Anchor.

BLACKMORE, S. (forthcoming) The Meme Machine. OUP.

BOYD, R. and RICHERSON, P. J. (1985) Culture and the Evolutionary Process. Chicago: University of Chicago Press.

BOYD, R. and RICHERSON, P. J. (1995) Why does culture increase human adaptability. Ethology and Sociobiology, 16: 125-143.

BURNS, T.R. and DIETZ, T. (1992) Cultural evolution: Social rule systems, selection, and human agency. International Sociology, 7: 259-283.

BURNS, T.R. and DIETZ, T. (1997) Human agency and evolutionary processes: institutional dynamics and social revolution. In: B. Wittrock (ed.), Agency in Social Theory. London: Sage Publications, in press.

CIALDINI R.B. (1988) Influence: Science and Practice. 2nd Ed. Illinois Scott Foreman and Co.

CLOAK F.T. (1975) Is a cultural ethology possible? Human Ecology, 3: 161-182.

COLLIGAN, M.J., & MURPHY, L.R. (1982) A review of mass psychogenic illness in work settings. In M.J. COLLIGAN, J.W. PENNEBAKER, & L.R. MURPHY (eds.) Mass Psychogenic Illness (pp. 171-182) NJ. Erlbaum.

CONNOLLY, T. & Aberg, L. (1993) Some contagion models of speeding. Accident Analysis and Prevention 25, 1: 57-66.

DARWIN (1859)The Origin of Species by Means of Natural Selection or The Preservation of Favoured Races in the Struggle for LifeLondon; Murray Reprinted (1985) London; Penguin.

DAWKINS, R. (1976) The Selfish Gene. UK. OUP.

DAWKINS, R. (1982) The Extended Phenotype. San Francisco; W.H. Freeman.

DAWKINS, R. (1993) Viruses of the mind. In B. Dahlbohm (ed.) Dennett and his Critics (pp.13- 27) Blackwell Publishers.

DENNETT, D.C. (1991) Consciousness Explained. UK: Penguin.

DENNETT, D.C. (1995) Darwin's Dangerous Idea: Evolution and the Meanings of Life. London. Allen Lane Press.

DIENER, E. (1976) Effects of prior destructive behavior, anonymity, and group presence on deindividuation and aggression. Journal of Personality and Social Psychology, 33: 462-470.

DIENER, E. (1979) Deindividuation, self-awareness and disinhibition. Journal of Personality and Social Psychology 37: 1160-1171.

DIETZ, T., BURNS, T.R. and BUTTEL, H. (1990) Evolutionary theory in sociology: An examination of current thinking. Sociological Forum, 5, 2: 155-171.

DIETZ, T. and Burns, T.R (1992) Human agency and the evolutionary dynamics of culture. Acta Sociologica, 35: 187-200.

DOHERTY, R.W. (1997) The Emotional Contagion Scale: A measure of individual differences. Journal of Nonverbal Behavior 21, 2: 131-154.

DURHAM, W.H. (1990) Advances in evolutionary culture theory. Annual Review of Anthropology, 19: 187-210.

DURHAM, William H. (1991) Coevolution: Genes, Culture and Human Diversity, Stanford: Stanford University Press.

ENNETT, S.T., FLEWELLING, R.L., LINDROOTH, R.C., & NORTON, E.C. (1997) School and neighborhood characteristics associated with school rates of alcohol, cigarette, and marijuana use. Journal of Health and Social Behavior 38, 1: 55-71.

FESTINGER, L., PEPITONE, A., & NEWCOMBE, T. (1952) Some consequences of deindividuation in a group. Journal of Abnormal and Social Psychology, 47: 382-389.

FLINN, M.V. (1997) Culture and the evolution of social learning. Evolution and Human Behavior, 18: 23-67.

FREEDMAN, J.L. (1982) Theories of Contagion as they relate to mass psychogenic illness in M.J. COLLIGAN, J.W. PENNEBAKER, & L.R. MURPHY (eds.) Mass Psychogenic Illness, (pp171-182) N.J: Erlbaum.

FREEDMAN, J.L., & PERLICK, D. (1979) Crowding, contagion and laughter. Journal of Experimental Psychology, 15: 295-303.

FREEDMAN, J.L., BIRSKY, J. & CAVOUKIAN, A. (1980) Environmental determinants of behavioral contagion: Density and number. Basic and Applied Social Psychology, 1: 155-161.

FREUD, S. [1922] (1959) Group Psychology and the Analysis of the Ego. London. Norton.

FURNHAM, A. (1983) Contagion, In R. HARRE and R. LAMB (eds.) The Encyclopaedic Dictionary of Psychology (p119).

GOETHALS, G.R. & PERLSTEIN, A.L. (1978) Level of instigation and model similarity as determinants of aggressive behavior. Aggressive Behavior, 4: 115-124.

GOULD M.S. (1996) Suicide Contagion. At American Foundation for Suicide Prevention Website http://www.afsp.org/research/gould.html.

GOULD, M.S. (1990) Suicide clusters and media exposure. In S.J. BLUMENTHAL & D.I. KUPFER (eds.), Suicide Over the Life Cycle. Washington, DC. American Psychiatric Press.

GOULD, M.S., WALLENSTEIN, S., & DAVIDSON, L. (1989) Suicide clusters: A critical review. Suicide and Life Threatening Behavior 19: 17-29.

GOULD, M.S., WALLENSTEIN, S., & KLEINMAN, M. (1987) A study of time-space clustering of suicide. Final report. Atlanta, Georgia: Centers for Disease Control.

GUMP, B.B., & KULIK, J.A. (1997) Stress, affiliation and emotional contagion. Journal of Personality and Social Psychology, 72, 2: 305-319.

HATFIELD, E., CACIOPPO, J.T. and RAPSON, R.L. (1993) Emotional Contagion. CUP.

HEYER, P. (1982) Nature, Human Nature and Society: MARX, Darwin, Biology and the Human Sciences. Connecticut. Greenwood.

HIGGINS, L & RANGE, L.M. (1996) Does information that a suicide victim was psychiatrically disturbed reduce the likelihood of contagion? Journal of Applied Social Psychology 26, 9: 781-785.

HIRSHLEIFER, D. (1995) The blind leading the blind: Social influence, fads, and informational cascades. In M. TOMMASI and K. IERULLI (eds.) The New Economics of Human Behavior. Cambridge, CUP.

HODGSON, G. M. (1993) Economics and Evolution: Bringing Life Back Into Economics. Ann Arbor: University of Michigan Press.

HOURAN, J., & LANGE, R. (1996) Hauntings and poltergeist-like episodes as a confluence of conventional phenomena: A general hypothesis. Perceptual and Motor Skill 83, 2: 1307-1316.

HSEE, C.K., HATFIELD, E., & CHEMTOB, C. (1992) Assessments of the emotional states of others - conscious judgements versus emotional contagion. Journal of Social and Clinical Psychology, 11, 2: 119- 128.

JONES, M.B. (1998) Behavioral contagion and official delinquency: Epidemic course in adolescence. Social Biology, 45, 1-2: 134-142.

JONES, M.B., & JONES, D.R. (1995) Preferred pathways of behavioural contagion. Journal of Psychiatric Research, 29, 3: 193-209.

KERCKOFF, A.C. & BACK, K.W. (1968) The June Bug: A Study in Hysterical Contagion. N.Y. Appleton-Century-Crofts.

LACHMAN, S.J. (1996) Psychological perspective for a theory of behavior during riots. Psychological Reports, 79, 3: 739-744.

LALAND, K.N. (1992) A theoretical investigation of the role of social transmission in evolution. Ethology and Sociobiology, 13: 87-113.

LANGTON, J (1979) Darwinism and a behavioural theory of sociocultural evolution: An analysis. American Journal of Sociology, 85, 2: 288-309.

LE BON, G. [1895] 1903 The Crowd: A Study of the Popular Mind. London. T. Fisher Unwin.

LEVY D.A., & NAIL, P.R. (1993) Contagion: A theoretical and empirical review and reconceptualization. Genetic, Social and General Psychology Monographs ,119: 235-183.

LUMSDEN, C. & WILSON, E.O. (1981). Genes, Mind, and Culture. Cambridge MA. HUP.

LUX, T (1998) The socio-dynamics of speculative markets: interacting agents, chaos, and the fat tails of return distribution. Journal of Economic Behavior and Organization, 33, 2: 143-165.

MARSDEN, P.S. (1997) Crash Contagion. Unpublished Paper delivered at University of Sussex Conference Death and Diana.

MARSDEN, P.S. (1998a) Memetics - Applications in sociology. Paper to be presented at Cybernetics society, Kings College, London November 1998.

MARSDEN, P.S. (1998b) Operationalising memetics - Suicide, the Werther effect, and the work of David P. PHILLIPS. Proceedings of the 15th International Congress on Cybernetics, Namur, Belgium.

MARSDEN, P.S. (in press) Memetics as a new paradigm for understanding customer behaviour. Marketing Intelligence and Planning.

MARSDEN, P.S. (in progress) Towards a neo-Darwinian sociology. DPhil thesis, University of Sussex.

MARSHALL, G. (1994) (ed.) Concise Oxford Dictionary of Sociology. Oxford. OUP.

ORLEAN, A. (1992) Contagion of opinion in financial markets. Revue Economique, 43, 4: 685-698.

PALMER, D.C. and DONAHOE, J.W. (1992) Essentialism and selectionism in cognitive science and behavior analysis. American Psychologist, 47, 11: 1344- 1359.

PFEFFERBAUM, B. & PFEFFERBAUM, R.L. (1998) Contagion in stress - An infectious disease model for posttraumatic stress in children. Child and Adolescent Psychiatric Clinics of North America 7, 1: 183.

PHILLIPS, D.P. (1974) The influence of suggestion on suicide: Substantive and theoretical implications of the Werther effect. American Sociological Review, 39, (Jun), 340-354.

PHILLIPS, D.P. (1980) Airplane accidents, murder, and the mass media: Towards a theory of imitation and suggestion. Social Forces 58, 4: 1000- 1024.

PHILLIPS, D.P. (1982) The impact of fictional television stories on U.S. adult fatalities: New evidence on the effect of the mass media on violence. American Journal of Sociology 87, 6: 1340-1359.

PHILLIPS, D.P. (1983) The impact of mass media violence on U.S. homicides. American Sociological Review 48 (Aug): 560-568.

PLOTKIN, H. (1982) (ed.): Learning, Development, and Culture: Essays in Evolutionary Epistemology. New York: John Wiley & Sons.

PLOTKIN, H. (1994) Darwin Machines and the Nature of Knowledge. London. Penguin.

RAPOPORT, A. (1983) Mathematical Models in the Social and Behavioral Sciences. NY. John Wiley & Sons.

REBER, A.S. (ed.) (1995) The Penguin Dictionary of Psychology (2nd ed.) Penguin.

REDL, F (1949) The phenomenon of contagion and "shock effect" in group therapy. In K.R. Eissler (ed.), Searchlights on Delinquency (pp. 315-128) N.Y. International Universities Press.

REICHER, S.D. (1984) The St. Paul's riot: An explanation of the limits of crowd action in terms of a social identity model. European Journal of Social Psychology, 14: 1-21.

RIDLEY, M. (1996) The Origins of Virtue. Viking, Penguin, London.

RINDOS, D (1985) Darwinian Selection, Symbolic Variation and the Evolution of Culture Current Anthropology, 26, 1: 65-88.

RINDOS, D (1986) The Evolution of the Capacity for Culture: Sociobiology, Structuralism, and Sociocultural Selectionism Current Anthropology, 27, 4 (Aug-Oct): 315-332.

RITTER, E.H. & HOLMES, D.S. (1969) Behavioral contagion: Its occurrence as a function of differential restraint reduction. Journal of Experimental Research in Personality, 3: 242-246.

RODGERS, J.L. & ROWE, D.C. (1993) Social contagion and adolescent sexual-behavior - a developmental EMOSA model. Psychological Review, 100, 3: 479-510.

ROGERS, E. M. (1995) The Diffusion of Innovations (4th ed). New York. The Free Press.

ROWE, D.C., CHASSIN, L., PRESSON, C.C., EDWARDS, D. & SHERMAN, S.J. (1992) An epidemic model of adolescent cigarette-smoking. Journal of Applied Social Psychology, 22, 4: 261-285.

RUNCIMAN, W.G. (1998a) The selectionist paradigm and its implications for sociology. Sociology 32:1: 163-189.

RUNCIMAN, W.G. (1998b) The Social Animal. U.K. Harper Collins.

RUNCIMAN, W.G. (1998c) Socialising Darwin. Prospect (April).

SHEEHAN, P.W. (1983) Age trends and the correlates of children's television viewing. Australian Journal of Psychology, 35: 417-431.

SHOWALTER, E. (1997) Hystories. N.Y. Columbia University Press.

SOBER, E. (1984) The Nature of Selection: Evolutionary Theory in Philosophical Focus, Cambridge, MA: MIT Press.

SPERBER, D. (1996) Explaining Culture. UK. Blackwell.

STACK, S. (1987) Celebrities and suicide: A taxonomy and analysis, 1948-1983. American Sociological Review 52 (Jun): 401-412.

STACK, S. (1990) Media impacts on suicide. In D. LESTER, Current Concepts of Suicide 107-120. Philadelphia. Charles Press.

TARDE, G. [1903] (1963) The Laws of Imitation. Mass. Peter Smith.

TEMZELIDES, T. (1997) Evolution, coordination, and banking panics. Journal of Monetary Economics 40, 1: 163-183.

TURNER, R.H. & KILLIAN, L.M.(1987) Collective Behavior (3rd Edition) NJ. Prentice-Hall.

TURNER, R.H. (1964) Collective behaviour. In R.E.L. FARIS (ed.) Handbook of Modern Sociology (pp. 382-425) Chicago. Rand McNally.

VAN de Berghe, P. (1990) Why most sociologists don't (and won't) think evolutionarily. Sociological Forum, 5, 2: 173-185.

WHEELER, L. & CAGGIULA, A.R. (1966) The contagion of aggression. Journal of Experimental Social Psychology, 2: 1-10.

WHEELER, L. & LEVINE, L. (1967) Observer-model similarity in the contagion of aggression. Sociometry, 30: 41-49.

WHEELER, L. & SMITH, S. (1967) Censure of the model in the contagion of aggression. Journal of Personality and Social Psychology, 6: 93-98.

WHEELER, L. (1966) Towards a theory of behavioural contagion. Psychological Review, 73: 179-192.

ZIMBARDO, P.G. (1969) The human choice: Individuation, reason and order versus deindividuation, impulse and chaos. In N.L. ARNOLD & D. LEVINE (eds.), Nebraska Symposium on Motivation (pp.237-308) Lincoln. University of Nebraska Press.

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