Cricket2,

The direction of the effect varies depending on the subjects' pre-existing level of test anxiety and the nature of the priming - whether the questions tend to reinforce self-perceptions of competence vs. incompetence, internal vs. external locus of control, etc.

http://www.allacademic.com/meta/p_mla_apa_research_citation/1/1/2/8/8/p112882_index.html

http://www.ncbi.nlm.nih.gov/pubmed/20435953