Intelligent people take longer to solve hard problems: study
I strongly suspect this effect is correlated with a weakness in short-term or working memory. Independent of general intelligence is the necessity for those with a weak short-term or working memory to compensate by relying on long-term, in depth understanding in order to JIT the necessary short-term structures into being on the spot, (often repeatedly as these images decay rapidly) in order to solve a problem. Whereas those with a short-term memory advantage can simply rely on memorized sets of arbitrary relationships to address the problem.In other words if you have a weak short-term or working memory you have to, by necessity, deeply think through everything - whether simple or complex. This may allow spotting the rare inconsistency or opportunity others may not, but as it comes at a performance and time penalty which, under circumstances commonly encountered in one's educational career (timed examinations) it more typically results in filtering such people out of fields where excursive, highly lateral modes of thinking would be beneficial.To survive this filter one must either acquire (or be gifted with) the talent of exceptionally swift traversal of a large and heterogeneous general knowledge graph, as one cannot rely on a handful of tightly knit but relatively isolated silos of memorized specialization.