The prevalence of typical dream themes challenges the specificity of the threat simulation theory

The evolutionary theory of threat simulation during dreaming indicates that themes appropriate to ancestral survival concerns (threats) should be disp roportionately, represented in dreams. Our studies of typical dream themes ill students and sleep-disordered patients indicate that threatening dreams invoking chase and pursuit are indeed among the three most prevalent theme s, thus supporting Revonsuo's theory. However, many of the most prevalent t hanes are of positive, not negative, events (e.g., sex, flying) and of curr ent, not ancestral, threat scenarios (e.g., schoolwork). Moreover, many cle arly ancestral themes (e.g., snakes, earthquakes) are not prevalent at all in dreams. Thus, these findings challenge the specificity of the threat sim ulation theory.