|dc.description.abstract||Social knowledge about food was investigated from a social contingency perspective (Guerin, 1994, 1998, 2004), a functional linguistic approach that considers language use having functions both to establish 'facts' in order to control listeners, and to maintain social relationships with words.
In Study 1, whether people shared knowledge about food or not was examined. One hundred and fourteen New Zealand and 23 Japanese participants were asked to answer free format questionnaires asking the reasons they and others eat or do not eat particular food items. Those answers were categorised into 8 categories and 30 sub-categories of the knowledge about foods by qualitative content analysis. The results of a cluster analysis of those categories showed that participants used the categories homogeneously although there were some differences between New Zealand and Japanese participants, and that the participants selectively used different types of knowledge according to food items especially when explaining why people do or do not eat some foods.
In Study 2, rhetorical features about foods were investigated: (1) numerical quantification rhetoric; (2) narrative use rhetoric; and (3) enumeration rhetoric. Factual statements from a corpus of 118 New Zealand TV commercials and 249 Japanese TV commercials were coded by the categories generated in Study 1. The results showed that the categories of factual statements were selectively used on TV commercials depending on the food types, and related closely to the results of Study 1. The rhetorical strategies appeared in commercials according to the categories of factual statements. When more than one factual statement was presented in a commercial, the relations of the factual statements were usually of a conjunctive form such as quotfact A however fact Bquot or quotfact A moreover fact Bquot, or else the factual statements were presented independently rather than the one statement logically warranting the other. These results suggest that those rhetoric uses and the arrangements of the factual statements were selectively used according to the effectiveness against counter arguments using shared knowledge.
Study 3 and Study 4 analysed the functions of shared knowledge about food for maintaining social relationships through investigating the cases in which knowledge about foods presented as the form of 'collaborative talk', which occurs when one speaker completes the preceding saying by another speaker.
In Study 3, the collaborative talk as sentence completions of knowledge about food was qualitatively analysed from conversations of 30 to 45 minutes produced by four groups consisting of four or five Japanese participants who were friends. From a social contingency view, the analysis focused on the following conversational properties: (1) who the listener was; (2) the degree of sharing of the information between the speakers; (3) the degree of sharing of the information between the 2nd speaker and the listener; and (4) the disagreement between the 2nd speaker and the listener.
The results of Study 3 suggested some possible functions of sentence completions of knowledge about food: (1) the function when the first speaker is the listener may be enhancement of the relationship between the first and the second speakers through showing the second speaker's attention and understanding to the first speaker's utterance, because those sentence completions were often followed by the affirmation or negation by the first speaker; (2) when a third person is the listener, and the first and the second speaker refuted the third person using sentence completion, the function seems to be just establishing 'facts'; and (3) in the cases of 'assisted explaining' (Lerner Takagi, 1999) , the function may be not only establishing 'facts' but also enhancement the relationship between the listener and the speakers, because the constructed 'facts' may work as a kind of conversational 'gift'.
In Study 4, five Japanese groups consisting of four participants who were friends were asked to talk about four topics about foods that all participants either agreed or disagreed ('All agree' condition) and four food topics for which there was disagreement about it between participants ('Some agree' condition). When the listeners could not be identified, and the second speakers did not used the utterance-final element such as 'yo ne' that is regarded as having a function of showing agreement between the speakers, the participants used sentence completions more frequently in 'All agree' conditions. The results suggested that the function of this type of sentence completion is not merely establishing 'facts' but also enhancing the relationship between the speakers through showing agreement about the relevant things to the topic.
In conclusion, the results of the present studies suggest some possible social contingencies involved both when people get knowledge about food and when they use it.||en_NZ