LogoMarsden, P. (2001). Is Suicide Contagious? A Case Study in Applied Memetics.
Journal of Memetics - Evolutionary Models of Information Transmission, 5.

Is Suicide Contagious? 
A Case Study in Applied Memetics

Paul Marsden
Visiting Research Fellow
Graduate Research Centre in the Social Sciences
University of Sussex
1 - Introduction
2 - 2. Memetics and Social Contagion: Two Sides of the Same Coin
3 - Suicide Contagion - Infected by a Suicide Meme
4 - Priming your Mind with Suicide
5 - Testing the Model - Is Suicide Contagious?
5.1 - Research Objectives
5.2 - Materials and Method
5.3 - Participants and Recruitment
5.4 - Results
5.5 - Discussion
6 - But is this Memetics?
7 - Conclusion


The phenomenon of suicide contagion is demonstrated experimentally. An interpretation of the results is proposed using an understanding of memetics as contagion psychology informed by selectionist thinking. Using the term `meme' to denote an object of contagion and `contagion' to denote a process of spread by exposure, a selectionist explanation of why certain people might be susceptible to a contagion of suicide is provided. Specifically, it is suggested that people who have become socially isolated and culturally disenfranchised, i.e. those with reduced residual cultural fitness (compromised access to the means of cultural reproduction), might be at particular risk from suicide contagion. Finally, public health policy implications of this memetic understanding of suicide are briefly outlined.

1 Introduction

In June 1962, the managers of a textile factory in Strongsville, USA, were obliged to close down their factory because of a 'mysterious sickness' that was affecting onsite workers.

On the evening of the closure, a news report described how at least ten women and one man had been admitted to hospital suffering from rashes and severe nausea. The news report also suggested that the cause of the sickness was a poisonous bite from an insect that had arrived in a shipment from England, and had taken up residence in the factory.

Several weeks later, with the plant still closed, a total of 62 workers had sought medical attention, having developed the symptoms of having been bitten by the bug. From initial rashes and nausea, the effects of the poisonous bite appeared to develop into chronic severe weakness punctuated with acute panic attacks.

The US Public Health Service `Communicable Disease Center' with a team of entomologists were called in to investigate this `June Bug', and took the expensive decision to fumigate and vacuum the huge textile plant.

After careful investigation, it was concluded that there had been no dangerous bug at all, English or otherwise. Rather, the episode had been an example of a process that social psychologists call `social contagion', a generic label used to describe the apparent infectious spread of opinions, emotions and behaviour by exposure to similar opinions, emotions or behaviours.

Social contagion usually occurs in contexts of uncertainty and stress, where people make use of information in the actions of people around them to make sense of situations, resolve ambiguity and to inform their own responses (Colligan, Pennebaker and Murphy 1982). Sure enough, when two social psychologists, Kerckhoff and Back (1968), interviewed victims of the mysterious `June Bug' illness they found that those who had been `bitten' had been suffering from undiagnosed stress and alienation.

2 Memetics and Social Contagion: Two Sides of the Same Coin

I have argued in a previous paper that for applied memetics, an inclusive and pragmatic working definition of a meme is the object of contagion (Marsden 1998a). This is consistent with the popular understanding of memetics as the study of `infectious' elements of culture. By `infectious', what is meant is the quality of some acts, emotions and opinions, in certain contexts, to spread by exposure rather than by some deliberate attempt to influence (such as coercion or persuasion).

The purpose of this paper is not to engage in an abstract discussion of the merits of this or that conception of a meme or memetics; indeed the purpose of using the meme neologism to describe objects of contagion is wholly pragmatic; to provide a rich, substantive research focus, and get on with doing memetics. Interestingly, contagion psychology shows that a meme, thus conceived, may have no essential properties, and is always a meme in context, thereby defying useful abstract discussion. For example, an act may spread by exposure in one context (and thus be a meme), but spread by coercion in another (and therefore not be a meme). Of course, if the term `meme' is used as a scientific-sounding basket label for all received ideas or socially learned behaviours, then the notion of a meme as an object of contagion, and memetics as a selectionist interpretation of contagion psychology, may seem unnecessarily restrictive. However, the advantage of the more modest conception of memetics is that it is useful within established social scientific models of human psychology, instead of being of interest only from without.

What follows is an example of how applied memetics might usefully proceed based on this understanding of a meme as an object of contagion, focusing on the peculiar phenomenon of suicide contagion.

3 Suicide Contagion - Infected by a Suicide Meme

Suicide contagion is said to occur when exposure to suicidal acts appears to trigger copycat suicidal acts. This peculiar phenomenon challenges rational interpretation perhaps as much as the notion of suicide, that is, deliberate self-destruction, itself. Now, sense can be made of many memetic phenomena within an established social learning framework; that we use information vicariously available to us in other people's experiences to inform our own adaptive responses to ambiguous situations. However, suicide contagion does not seem to fit this model insofar as suicide is clearly not adaptive from the suicidal individual's point of view. So bizarre is the phenomenon, that despite the consistent finding of elevated suicide levels following suicide publicity (Marsden 1998b), some researchers find the whole idea of suicide contagion incredible. Nevertheless, strict official guidelines do exist on how suicide should be publicly discussed (e.g. CDC 1994) based on the assumption that individuals contemplating suicide who see suicide or suicidal individuals rewarded (in attention and/or positive evaluation) may infer that suicide is an appropriate response to their distress.

The suicide contagion hypothesis is that exposure to suicide is a suicide risk-factor for people experiencing an unresolved conflict as to whether suicide is an appropriate response to current unresolved distress. Whilst ethical considerations obviously preclude the direct experimental investigation of this hypothesis, one aspect of suicide contagion does lend itself to indirect experimental research. This is the impact of semantic priming.

4 Priming your Mind with Suicide

Priming refers to the idea that the interpretation of situations can be involuntarily patterned by recent and frequently experienced events (Fiske and Taylor 1991). To take a trivial example, a habitual walk home after seeing a frightening movie may result in an increased level of `feeling spooked' because the themes evoked by the film remain salient in the mind, thereby producing contagion; the spookiness of the movie influences subsequent interpretations of events. More generally, priming suggests that the ways in which situations are interpreted can be influenced by ideas salient in memory that have been the focus of recent and/or frequent attention. Put simply, we tend use the meanings we have to hand in interpreting situations. Further, because some ideas cue other ideas, this aspect of what is known as social cognition may result in `spreading activation' whereby exposure to ideas cue not only those ideas but also related ideas.
"Thoughts of which one is consciously aware send out radiating activation along associative pathways, thereby activating other related thoughts. In this way, ideas about aggression that are not identical to those observed in the media may be elicited later. In addition, thoughts are linked, along the same sort of associative lines, not only to other thoughts but also to emotional reactions and behavioural tendencies." (Geen and Thomas 1986: 12)
For example, in one experiment it was found that people became more aggressive following exposure to images of weapons, as aggressive ideas around weapons were primed in the mind of the exposed to them (Leyens and Parke 1975). The idea is that when activated by becoming the focus of attention, a concept and related concepts in the semantic network of an individual's memory are easier to retrieve, that is, the mind is primed with these concepts and will tend to use them to interpret situations (Higgins 1989, Fiske and Taylor 1991, Berkowitz 1984, Jo and Berkowitz 1994).

Applied to suicide contagion, this interpretation would predict that exposure to suicide should have a short-term impact on how a situation is interpreted as being potentially suicidal. To test the plausibility of this model, the following experiment was conducted as part of a D.Phil research project in 1999 (Marsden 2000).

5 Testing the Model - Is Suicide Contagious?

5.1 Research Objectives

To assess the empirical plausibility of the idea of suicide contagion by priming; specifically that mediate exposure over the Internet to the concept of suicide can influence how a situation is subsequently interpreted as being potentially suicidal.

Specifically, the research hypothesis was as follows:

Priming participants with the idea of suicide, by informing them that the topic of research was `young people and suicide', would result in an increased likelihood of interpreting a distressing and ambiguous situation described by a text as suicidal

5.2 Materials and Method

Standard experimental design of controlled exposure to the concept of suicide over the web was followed by data capture in a self-completion web questionnaire. Piloted in April 1999, the research took place in May 1999. Participants were randomly assigned to either an experimental group or a control group, all invited to first read a short text about a distressed student at university, and then indicate on a standard 5-point Likert scale, the likelihood that they thought that the student would commit suicide (1 = not at all likely, 5 = very likely). The only difference in materials used between the two groups was how the research study was introduced to them; in the experimental group the welcome screen introduced the study by saying that it was about young people and suicide, and in the control group about young people and stress. The texts and HTML questionnaires were published to the Internet at using Microsoft FrontPage and a custom CGI script that randomly directed participants from an initial index welcome page to one of the two texts. The responses were captured in a simple CSV (comma separated variable) database sent from the HTML form.

5.3 Participants and Recruitment

Participants were UK Internet-users over the age of 18 recruited through chain email. Because of the potentially sensitive nature of the research, no incentives were offered, and instructions were given to those recommending individuals that only those over eighteen should be invited. Additionally, attention was called to a hyperlink provided on each page of the web questionnaire to an online support group, (Samaritans - although this was unnamed) to be used if participants found the exercise in any way distressing. Finally, participants were told that they could change their mind about participating, and withdraw from the exercise at any time.

5.4 Results

67 UK Internet-users completed the task (36 male, 31 female, average age 22) over a two-week period in May 1999. The research hypotheses predicted that participants primed with the concept of suicide would be more likely to assess an ambiguous situation as more suicidal than participants not primed with the concept of suicide. An inspection of the mean results was consistent with this, with those primed with suicide interpreting the likelihood that a distressed individual would commit suicide at 2.42, and this compared to 1.77 in the control group. A one-way ANOVA (analysis of variance) revealed that this difference was statistically significant at the 0.001 level (F(1,65)= 11.79, p< .001) indicating a strong patterning of the data in a way consistent with expectations of the model.

Figure 1: Suicide is Contagious

5.5 Discussion

The results of this study were consistent with the idea that exposure to the idea of suicide can prime the concept of suicide in peoples' minds and influence the interpretation of ambiguous situations by facilitating a perception of that situation as suicidal. Although the research hypothesis was confirmed by a strong patterning of the data, thus suggestive of such an influence for the group of participating adult UK Internet-users, the use of non-probability sampling would have precluded any possibility of generalising the results to a more general UK Internet-user population, even if this were considered a legitimate strategy. Further, although the results were continuous with expectations following from the model in terms of interpreting somebody else's situation as suicidal, this does not imply, other than extremely weakly, that participants might also be more likely to interpret their own situations as suicidal following exposure to suicide. Nevertheless, the results of this small study are consistent with such a view.

6 But is this Memetics?

The above experiment is a simple example of applied memetics operationalised as the study of infectious acts, opinions and emotions. Now, the critic could argue that this understanding of memetics adds little to the already established field of social contagion research, apart from providing a useful label for the object of contagion. However, from the understanding of memetics proposed here, this is not a problem because memetic research is social contagion research.

Further, it may be possible to gain some leverage from the selectionist heritage that underpins Dawkins' neologism, and use it as a creative stimulus for generating hypotheses on why certain people appear to be susceptible to contagion. By way of example, I would like to conclude by proposing a selectionist understanding of why certain people, and not others, may be susceptible to suicide in general and suicide contagion in particular.

As noted above, suicide is problematic because it is clearly not an adaptive act from the perspective of the suicidal individual. This has led some to suggest that suicide might be enabled by a heritable genetic variation that remains in the gene pool over time because it enables suicide when the residual inclusive fitness of an individual is particularly low (e.g. de Catanzaro 1980, 1981).

Whilst a genetic `enablement' of suicide may well be feasible, it is possible to apply an alternative cultural model using a similar logic. Specifically, if cultural variations, such as those that enable suicide, persist based on their likelihood of being adopted, then the inclusion of suicide in a culture as a meme is only viable over time if it has no systematically deleterious effect on its own reproduction. Now, one way that this could be possible is if those committing suicide were not significant contributors to the propagation of suicide themselves, so that their deaths would not negatively impact on the persistence of suicide. It is this point that provides a selectionist hypothesis for susceptibility to suicide contagion insofar as such susceptibility might be contingent on a reduced residual capacity to pass on culture. In such cases, suicide would not be maladaptive, because the suicidal individual would not be culturally `viable'.

This model leads to an empirical prediction pertaining to those most at risk from suicide contagion. The model would predict that those susceptible to suicide contagion should be those with a reduced residual capacity to spread culture, that is, those who become socially isolated and culturally disenfranchised. Indeed, over and above the possibility that suicide may be used as a strategy for increasing a waning cultural fitness, the fact that cultures are shared means that the suicide of those whose capacity to reproduce their culture has become compromised could actually increase the overall capacity of cultural relatives to pass on shared culture, including any suicide meme. In fact, if an individual actually represented a cost to the overall reproductive potential of the shared culture to which suicide is a part, then suicide could actually have a positive effect on the likelihood that that some `suicide culture' gets reproduced. In this model, differential ownership of the means of cultural reproduction, or simply put, marginality, would be a key variable in susceptibility to suicide contagion, and to suicide in general.

This memetic prediction is borne out by empirical research that has consistently demonstrated that low levels of social cohesion are one of the most significant risk factors in suicide (e.g. Durkheim 1970 [1897], Halbwachs 1978 [1930], Henry and Short 1954, Gibbs and Martin 1964, Maris 1981). In these cases, suicide contagion could be seen as a `fortuitous' cultural mutation that allows a culture to effectively rid itself of parasites that reduce its reproductive potential to maintain itself.

The tentative support for this memetic model might warrant formalisation for future research using, for instance, Hamilton's (1964) model of inclusive fitness in a cultural substrate. Specifically, as long as overall inclusive capacity of the set of culture that describes an individual is not reduced by suicide (or indeed self-sacrifice, as in the case of war), then any suggestion-by-exposure to suicide occurring within a constellation of pro-suicidal circumstances could be more likely to result in suicide. This is because the benefit of suicide to cultural relatives, in terms of enhancing their capacity to reproduce their shared culture multiplied by a degree of cultural relatedness to the suicidal individual, would be equal or superior to the direct cost to the suicidal individual of suicide in terms of any personal capacity to make such contributions.

Memetic Model of Suicide
Cd < rBr

Figure 2: Hamilton's Rule for the Biological Communication of the Individually Maladaptive Traits. Here: Cd = Cost in cultural reproductive potential of suicide to individual, r = coefficient of relatedness, and Br = Benefit in cultural reproductive potential of suicide to cultural relatives

With respect to practical public policy recommendations on reducing contagion, this interpretation provides an argument for curtailing any sensationalist media publicity around suicide, because such publicity might effectively increase the cultural fitness of the suicidal individual, that is, the capacity to pass on culture. Rather than merely refrain from the positive portrayal of suicide and suicide victims in the media as per current recommendations, this memetic model of suicide could be used to suggest that there could be a potential benefit (if reducing suicide levels is seen as beneficial) of not covering suicides stories at all, or at least reporting the deaths but not as suicides. Of course, there are important and controversial issues of censorship and free speech that are raised here, and it may be decided that suicide contagion is a lesser evil than what amounts to ideational eugenics.

7 Conclusion

This paper presents one vision of memetics, as an integrated part of applied social science investigating substantive issues of human experience. Understanding memetics as contagion psychology, using selectionist thinking to inform interpretation, is certainly not the only way to conceptualise the nascent discipline, but it is hoped that it is one that will allow memetics, after a quarter of a century of discussion, to start providing useful insight into real-world issues and problems.


Berkowitz, L., (1984). Some effects of thoughts on anti- and prosocial influence of media events: A cognitive neoassociationist analysis. Psychological Bulletin, 95, 410-427.

CDC (1994) Centers for Disease Control and Prevention. Suicide Contagion and the Reporting of Suicide: Recommendations form a National Workshop. Morbidity and Mortality Weekly Review, 43, (RR-6).

de Catanzaro, D., (1980). Human suicide: A biological perspective. Behavioral and Brain Sciences, 3(2), 265-290.

de Catanzaro, D., (1981). Suicide and Self-Damaging Behavior: A Sociobiological Perspective. San Diego: Academic Press.

Colligan, M.J., Pennebaker, J.W., and Murphy, L.R., (1982) Mass Psychogenic Illness: A Social Psychological Analysis. New Jersey: Lawrence Erlbaum Associates.

Durkheim, E., (1970). Suicide: A Study in Sociology. Translation J. A. Spaulding & G. Simpson, (1951) London: Routledge & Kegan Paul. Originally published in French 1897.

Fiske, S. T. & Taylor, S. E., (1991). Social Cognition. New York: McGraw-Hill.

Geen, R., and Thomas, S., (1986) The immediate effects of media violence on behavior. Journal of Social Issues, 42, 7-27.

Gibbs, J., and Martin, W.T. (1964). Status Integration and Suicide. Eugene, Oregon: University of Oregon Press.

Halbwachs, M., (1978) The Causes of Suicide (translation of 1930 Les Causes du Suicide) London: Routledge.

Hamilton, W., (1964). The genetical evolution of social behaviour. Journal of Theoretical Biology, 7, 1-52.

Henry, A., and Short, J. (1954). Suicide and Homicide. New York: McGraw-Hill.

Higgins, E. T., (1989). Knowledge accessibility and activation: Subjectivity and suffering from unconscious sources. In J. S. Uleman & J. A. Bargh, (eds.), Unintended Thought, New York Guildford Press, 75-123.

Jo, E. and Berkowitz, L., (1994). A priming effect analysis of media influences: An update. In J. Bryant, & D. Zillmann, (eds.). Media Effects: Advances in Theory and Research. Hillsdale, NJ: Erlbaum.

Kerckhoff, A. C. and Back, K. W., (1968). The June Bug: A Study in Hysterical Contagion. New York: Appleton-Century-Crofts.

Leyens, J. and Parke, R. D., (1975). Aggressive slides can induce a weapons effect. European Journal of Social Psychology, 5, 229-239.

Maris, R., (1981). Pathways to Suicide: A Survey of Self-Destructive Behaviors. Baltimore: Johns Hopkins Press.

Marsden, P., (1998a). Memetics and Social Contagion: Two Sides of the Same Coin? Journal of Memetics - Evolutionary Models of Information Transmission, 2. http://cfpm.org/jom-emit/1998/vol2/marsden_p.html

Marsden, P., (1998b). Operationalising Memetics, Suicide, the Werther Effect and the work of D. P. Phillips. Proceedings 15th International Congress on Cybernetics. Namur, Belgium. http://pespmc1.vub.ac.be/Conf/MemePap/Marsden.html

Marsden, P., (2000) The Werther Effect: Suicide Contagion in the Internet Age - A Critical Evaluation, Theoretical Reconceptualisation and Empirical Investigation. D.Phil Thesis (Sussex).  http://www.viralculture.com/DPhilsummary.htm

© JoM-EMIT 2001

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