SHOULD WE TAKE DON'T KNOW FOR AN ANSWER?

Much attention has been given to the problem of non-attitudes,that is, people expressing opinions while lacking an underlyingattitude (false positives). In comparison, the potential problemof false negatives, people with an attitude who decline to expressan opinion, has been neglected. Using a survey on nuclear powerfrom Sweden, we examine whether people who answer "don't know"but are induced subsequently to give an opinion really haveattitudes. The attitudes these people express on follow-up questionspredict behavior to a significant extent. This implies thatthe usual don't know category includes some false negatives,that is, people who really have attitudes but refrain, at leastinitially, from expressing them.