Effects of involvement and affection of communication including numerical risk information on the attitudes change

The purpose of the study is to assess Japanese citizens’ numeracy levels, to explore the relationships between those levels and judgments for various tasks, and to examine judgments toward real-life probabilistic forecasts. An Internet survey was administered to citizens in the Kanto area including Tokyo in 2012. All the participants (n = 5553) answered Lipkus et al.’s (2001) numeracy scale. After the survey the experiment was conducted for the stratified samples that were from the survey (n =960) by age, education, and numeracy levels. Participants provided their judgments and decisions for several tasks. The results showed that the median of the numeracy scores were 10 out of 11, with significant differences in gender, age, and education levels. The many errors were found in real-world Items. Low-numeracy participants showed significantly higher decision biases in real-world tasks (the lottery problem). Yet, in other problems (e.g., Tversky & Kahnemans’ [1981] Asian disease problem), the biases were common. Both levels of participants showed positive attitudes toward issuing probabilistic earthquake forecasts. When the forecast values were changed and the probability decreased, however, fear increased significantly for low-numeracy participants, in contrast to the high- participants, whose fear decreased. This result indicates that numeracy education is highly important for risk communication.