Exploring factors that influence judgements of climate change statements : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University,Manawatū, New Zealand
This aim of the current study was to examine the effect of repetition (i.e., illusory truth effect) and non-probative photographs (i.e., truthiness effect) on mean truth ratings of climate change statements using a within-subjects design. A total of 80 participants were asked to provide truth ratings to climate change statements in two parts. At Time 1, half of the statements appeared with photographs and half without photographs, while at Time 2, repeated statements from the first part were intermingled with a set of new statements. None of the statements at Time 2 appeared with photographs. It was hypothesized that statements paired with photographs and repeated statements would receive higher truth ratings than statements not paired with photographs and new statements. Likewise, it was predicted that repeated statements that had been paired with photographs at Time 1 would receive higher truth ratings compared to repeated statements that were not paired with photographs. Three planned comparisons and a paired samples t-test were used to assess the effect of repetition and photographs on truth ratings. The only significant difference in truth ratings observed was between repeated and new statements, with repeated statements receiving higher mean truth ratings than new statements. No influence of photographs or a cumulative effect of both repetition and photographs was found. Exploratory analyses of the effect of the type of statement (true or false) on truth ratings showed that, true statements were perceived as truer, and false statements were perceived as less true when paired with photographs (as compared to when not paired with photographs). Implications of findings, limitations of the current study and future research are also discussed.