Summary of Meeting Paper

The 1996 Annual Meeting of the Society for Risk Analysis-Europe

Modelling Public Risk Perceptions for Lifestyle and Technological Hazards. C. Pattison, D. Hedderley, and L. J. Frewer, Department of Consumer Sciences, Institute of Food Research, Early Gate, Whiteknights Road, Reading, Berks, UK

It has long been known that compared to expert risk assessors, the public tends to overestimate risks associated with 'technological' hazards e.g. food additives and genetic engineering and also tend to underestimate risks associated with 'lifestyle' hazards e.g. high-fat diet and smoking. Members of the public also have a tendency to view themselves as being at less risk and more knowledgeable about risks than others (optimistic bias) and thus may ignore risk communications if they consider them to be aimed at more vulnerable, less knowledgeable others (Frewer et al., 1994). Several key research needs can be identified from the seminal research by Fischhoff et al. (1978) and Slovic et al. (1980). In these studies subjects rated hazards against characteristics the researchers thought to be important in perception of risk. However when investigating public perceptions it is important not to make prior assumptions about which factors underpin these perceptions. These early studies revealed some basic dimensions on which the public perceived differences between a broad range of hazards. The constructs people associate with different hazards depends on the comparative context or hazard domain within which the hazard is presented. Studies looking specifically at food related hazards have yielded similar factor structures (Sparks and Shepherd, 1994) to those found using a broad range of hazards. However, food covers a broad range of hazard types including both lifestyle-related and technology-related hazard types. To fully understand the constructs people associate with food related hazards exploratory qualitative work is required to elicit the constructs associated with these characteristics within the context of technological and lifestyle hazard domains.

Two separate studies (n=35 in both) were conducted to determine how subjects characterise and differentiate hazards within lifestyle and technological domains. Repertory grid methodology and generalised Procrustes analysis were used. Content analysis of the interview scripts revealed that, in general, lifestyle hazards were described mainly in terms of the context of exposure whereas technological hazards were described mainly in terms of the consequences of exposure. Thus public definitions of risk appear to depend on the domain within which the hazard is embedded. Generalised Procrustes analysis produces consensus plots of how people differentiate between hazards and the elicited constructs can be related to these plots. As can be seen from the results of the lifestyle study (see Fig 1), the primary axis (41.5%) differentiates non-food related hazards, seen as 'risky', from food related hazards which are associated with beneficial effects. Also, compared to the other hazards, 'sunbathing', 'unprotected sex' and 'cholesterol' are associated with an element of control, so we would predict that, within this lifestyle hazard domain, these hazards are most prone to an optimistic bias, and by implication people may be less likely to take heed of risk communications about these particular hazards. Looking at how the constructs are spread, we can see that there is a conical distribution, with beneficial effects being opposed by 'risky' and other negative constructs. However, a different pattern emerges with the technological hazards (see Fig. 2), where the constructs are spread more evenly throughout the map, and there are a greater number of positive constructs. It may be the case that for these technological hazards attitudes are less crystallised and polarised as 'good' or 'bad' with positive attributes playing a more complex and mediating role in perceptions. Also, within this technology domain, food related hazards, associated with 'new' and 'lack of information' are differentiated from non-food related hazards, associated with 'old' and 'lots of information', in terms of the secondary axis (21%). Again, we can see that 'electricity', 'petrol use' and 'road transport' are associated with an element of control, so we would predict that, within the context of a technology hazard domain these hazards are most prone to optimistic bias and therefore for these hazards in particular, risk communications are most likely to be ignored.

Fig. 1: Lifestyle hazards.



Fig. 2: Technological hazards.



Finally, early studies (Fischhoff et al., 1978; Slovic et al., 1980) were descriptive, informing us of the most important underlying factors people use to differentiate between hazards, but not how these factors determine risk perceptions or interact with other factors. Risk perceptions are socially constructed, being influenced by many highly correlated factors including these hazard characteristics, such as individual differences and social context. Structural equation modelling techniques, such as EQS (Bentler, 1995), are required that can model risk perceptions and confirm the nature of hypothesised causal pathways between the many factors that predict risk perception. Therefore conceptual models of public risk perceptions within technological and lifestyle hazard domains will incorporate the constructs indicated by these exploratory studies along with these other factors identified from the risk perception literature. These models will then be tested in future survey work and be analyzed using EQS, in order to understand non bivariate relationships between the factors contributing to risk perceptions.

This work was funded by the Office of Science and Technology.

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