Simple heuristics could make us smart; but which heuristics do we apply when?

Simple heuristics are clearly powerful tools for snaking near optimal decisions, but evidence for their use in specific situations is weak. Gigerenzer et al. (1999) suggest a range of heuristics, but fail to address the question of which environmental or task cues might prompt the use of any specific heuristic. This failure compromises the falsifiability, of the fast and frugal approach.