Communication about genetically modified foods and models of attitude change

The importance of people’s perceptions regarding information sources has been shown through an experiment using the Elaboration Likelihood model described earlier (Frewer et al., 1999). This research built on the observation that, in the UK, government sources have been shown to be one of the least trusted providers of information about food-related risk, and consumer organisations one of the most trusted sources, (Frewer et al., 1996).

It is interesting to manipulate information so that the true effects of these differences in source characteristics in terms of their influence on attitudes can be empirically examined. A part of this process is to ensure that information is attributed to a source that might realistically produce it in the ‘real world’. In the experimental work reported here, both the government and consumer organizations have produced information about genetic modification, adding to the ‘ecological validity’ of experiment. Perceptions of risk relevance were also manipulated as part of the experiment. This was either high (respondents were told that they were able to buy genetically modified food in shops at the time of the experiment) or low (respondents were told that genetically modified foods would not be available for many years). The persuasive strength of the information was also manipulated to be high or low. In this experiment, persuasive information was directed towards public acceptance of genetically modified foods. To this end, the experimental work was conducted in two stages.

The first of these was the pre-selection of messages of high and low persuasive strength directed towards acceptance of genetic modification in food and agriculture, using a separate group of participants. This enabled identification of the ten most, and ten least, persuasive statements. The second was the systematic examination of the interaction of perceived risk relevance, persuasive strength, and trust in information source to which the information was attributed. People’s attitudes towards genetically modified foods were then assessed. A three-factor experimental design was used. Levels of the first factor (persuasive content) were either high or low. Levels of the second factor (source) meant that respondents received information, which was attributed to either a consumer organisation or to government. The third factor (risk relevance) also had two levels – respondents were provided with information that led them to believe that the products of genetic modification were immediately available, or were likely to be available only at a later date, currently far in the future. All respondents then rated the information for their perceptions of source characteristics and informational qualities. Assessments were also taken of their attitudes to genetic engineering used in food production (Frewer et al., 1997; Bredahl et al., 1998), as well as completing other tasks designed to assess the extent to which they had internalised the information.

It was found that the information was more trusted if it was both high in persuasive strength and attributed to the government, if irrelevant risks were presented to respondents. However, it was found that highly persuasive information from a consumer organisation, or information from government that was low in persuasive strength, was more trusted if the risks were presented as being highly relevant to respondents. However, in terms of differences in attitude towards genetic modification, there were few significant differences between conditions. Thus it seemed that information had an impact on trust or distrust, rather than trust influencing attitude change following presentation of information. This might be because people had very strong attitudes towards genetic modification, and their reactions to the information (and the information sources) were influenced by these views. Indeed, social judgement theory would predict that initial attitude is likely to be one of the most important determinants of reactions to persuasive information, particularly if it appears to be promoting what might be interpreted as a vested interest (Eagly and Chaiken, 1993).

In a further experiment, (Frewer, Scholderer, and Bredahl, in press), two kinds of information about genetically modified food were presented to participants in an intervention trial – these were ‘product specific’ information (which was used to present genetically modified foods in a positive light) and ‘balanced’ information, (which discussed the potential risks and benefits of genetic modification of foods in a very neutral, but probabilistic and technical way). The information was attributed either to a consumer organisation (shown to be highly trusted in pilot research), an industry association (highly distrusted), or the European Commission (moderately trusted) in the different experimental conditions used in the study. Attitudes towards genetically modified foods were assessed before and after the information intervention.

Data about people’s perceptions of information source characteristics (for example, whether they were trusted or not) were also collected. The results indicated that the extent to which people trusted information sources had little impact on attitudes towards genetically modified products or product acceptance. Prior attitudes towards genetically modified foods accounted for almost 95 and 90 per cent of the variance in perceived benefit and perceived risk respectively. Contrary to what might have been predicted, trust had negligible impact on these risk-related attitudes. The extent to which participants trusted the information sources was predominantly determined by already existing attitudes held by participants towards genetically modified foods. Attitudes were not influenced by perceptions of source characteristics. In other words, independent of the type of information provided, information provision in itself had little effect on people’s attitudes towards genetically modified foods. Perceptions regarding information source characteristics did not contribute to attitude change, nor did the type of information strategy adopted have an impact on post-intervention attitudes.

Of greatest concern to industry and other institutions with an interest in information dissemination was the finding that the extent to which people trusted the information sources was driven by people’s attitudes to genetically modified foods. Trust did not influence the way that people reacted to the information. On the other hand, attitudes were used to define people’s perceptions regarding the motivation of the source providing the information. This perhaps is understandable in the case of the product-specific information, which was very positive about genetic modification, focusing only on benefits associated with novel products. People who favour the use of genetic modification are more likely to trust a source promoting its benefits. On the other hand, people who do not support the use of genetic modification in food production are more likely to distrust this same source providing the positive information because it does not align with their strongly held views. This does not explain why the same effect was observed in the case of the ‘balanced’ information strategy. The reason may be because of the way in which the information strategies were developed in the first place from the opinions of experts in the area of biotechnology, who proposed a ‘rationalistic’ approach to technology communication issues. Expert views regarding what is salient to risk communication may be very different from what is considered important by the public.