Press cutting: Why dithering gets you nowhere

Participants were asked to pick the odd one out on a screen covered in more than 650 identical symbols, including one rotated version of the same symbol.

They performed better when given no time to linger and were forced to rely on their subconscious.

Dr Li Zhaoping [UCL Psychology] said: "You would expect people to make more accurate decisions when given the time to look properly.

"The conscious or top-level function of the brain, when active, vetoes our initial subconscious decision - even when it is correct - leaving us unaware or distrustful of our instincts and at an immediate disadvantage.

"Falling back on our inbuilt, involuntary subconscious processes for certain tasks is actually more effective than using our higher-level cognitive functions."

Roger Highfield, 'Daily Telegraph'