I think such phenomena are our instinctive, subconscious recognition/communication tools kicking in and providing our conscious self with extra information. We all have subconscious tools, of varying levels of effectiveness, that developed when we were primarily instinctive creatures. There are people like Derren Brown who have a particular talent at consciously deploying those tools (e.g. recognising the tiniest physical responses to stimuli in his 'mind reading' techniques, using specific communication methods to provoke predicted behaviour) but there are also people who do the same without realising what they're doing (which is what I think is happening when people are sincerely convinced that they have 'psychic' powers). IMO sixth senses and 'infallable' intuition fall in to the same category.
Sum ergo sum