They are regularly accused of being too confident – even cocky– but the highest achievers are more often than not those who over-rate their ability.

　　他們經常因為太過自信甚至自負而遭到指責，然而成就最高的人往往是那些過高估計自身能力的人。

　　Now researchers believe they have discovered, for the first time, why humans have a false sense of optimism.

　　研究人員認為他們現在已經首度發現為什麼人類會有過度樂觀的心理。

　　Computer led simulations have shown that overconfidence in all aspects of life can often improve your chances of winning.

　　電腦操縱的模擬實驗顯示，在生活中各個方面，過分自信經常能夠增加獲勝的幾率。

　　For many years scientists have been divided over whether overconfidence is a good or bad thing and why it existed.

　　多年以來，科學家對於過分自信是好事還是壞事以及為何會有這種心理一直存在分歧。

　　‘There hasn't been a good explanation for why we are overconfident, and this new model offers a kind of evolutionary logic for that. It's unlikely to be an accident—we're perhaps overconfident for a good reason,’ said Dr Dominic Johnson of the University of Edinburgh.

　　愛丁堡大學的多米尼克 強森博士說：“一直以來人們都無法較好地解釋為什麼我們會過度自信，這一新模擬實驗為其提供了一種進化上的理由。這種心理不大可能是意外，我們會過度自信，或許是有合理的原因的。”

　　Sprinter Usain Bolt is famed for his relaxed and confident approach to performing, as was ‘the greatest’ boxer Muhammad Ali.

　　短跑運動員尤塞恩 博爾特以其放鬆而自信的比賽狀態著稱，“最偉大的”拳擊手穆罕默德 阿裏也是這樣。

　　But there is a word of warning for anyone thinks they could be faster than a speeding bullet, more powerful than a locomotive, or able to leap tall buildings in a single bound.

　　不過，研究人員也要警告那些認為自己可以比高速飛行的子彈還快，比機車還有力量，或能一跳就越過高樓的人。

　　Positive self-delusion can also cause problems and lead to wrong decision making, unrealistic expectations, danger and failure.

　　積極的自我欺騙也會導致問題，並可能使人做出錯誤的決策、產生不切實際的期望、引發危險和造成失敗。