It doesn't pay to be smart and ignorance really is bliss¹ if you want a long life -- at least if you're a fly, according to new research by a Swiss university.

Scientists Tadeusz Kawecki and Joep Burger at the University of Lausanne said Wednesday they had discovered a "negative correlation² between an improvement in a fly's mental capacity and its longevity³".

As part of their research project, the results of which are published in the journal Evolution, they divided into two a group of flies from the Basel region of northwestern Switzerland.

One half was left in a natural state while the other had its intelligence boosted by Pavlovian methods, such as associating smell and taste with particular food or experiences.

These methods led to flies which clearly learned better and remembered things for longer.

The flipside was that the flies left in their natural state lived longer on average than their "cleverer" counterparts, with a lifespan of 80-85 days rather than the normal 50-60..

"In other terms, the more the fly becomes intelligent, the shorter its lifespan," the scientists said.

This is most probably because the increase in neural⁴ activity weakens the fly's life-support systems, they speculated.

"This would explain why flies, like most other animals, have hardly developed their neural capacities," they said.

瑞士一所大学开展的最新研究发现，聪明没什么好处，如果想长寿，还是傻一点好——至少对于苍蝇来说是如此。

瑞士洛桑大学的科学家塔多兹•卡维基和约普•伯格于本周三称，他们发现“苍蝇的智力水平与其寿命呈反比”。

该研究结果在《生物进化》期刊上发表。在研究过程中，科学家将来自瑞士北部巴塞尔地区的一群苍蝇分成了两组。

他们让其中一组苍蝇处于自然状态，让另一组苍蝇接受“巴甫洛夫法”训练以提高它们的智力，比如将嗅觉与味觉与特定的食物或生存经验联系起来。

经过训练的苍蝇“学习能力”和记忆力明显提高。

而研究发现，处于自然状态的苍蝇比“聪明的苍蝇”平均寿命更长，这些苍蝇的平均寿命超过了普通苍蝇的五六十天，达到80天至85天。

科学家说：“换句话说，越聪明的苍蝇，寿命越短。”

据科学家推测，这可能是因为神经系统活动的增多会削弱苍蝇的生命支持系统。

他们说：“这可以解释为什么苍蝇与多数其它动物一样，几乎不强化它们的神经系统能力。”