Failures, understood in a broad sense as the poor performance of a system, can be analyzed from different perspectives.  A top level view finds human cognitive characteristics determining performance.  While cognitive psychology is frequently mentioned in the literature of varied fields (from artificial intelligence to civil engineering), its findings are seldom noted.  In this paper, a summary of the most relevant human biases and limitations is presented and exemplified with civil engineering cases.  Alternative means of reducing their effects are then discussed.