什么能決定你的智商？這個問題你關(guān)不關(guān)注，大腦的大小會不會影響你的智商情況？這個問題確實值得研究，因為有很多人想知道。

　　it's not something we'd like to admit, but it seems the human race may actually be becoming increasingly dumb. man's brain has been gradually shrinking over the last 20,000 years, according to a new report. this decrease in size follows two million years during which the human cranium steadily grew in size, and it's happened all over the world, to both sexes and every race。

　　也許我們真的不愿意承認(rèn)，但是，近日一項新發(fā)現(xiàn)在這個“科學(xué)大爆炸”的時代提出猶如一聲驚雷，讓“自以為很聰明”的人類“捫心自問”：我們真的 “越來越笨”了嗎？。據(jù)悉，實驗將遠古時代的人腦與現(xiàn)代對比，驚人發(fā)現(xiàn)，雖然在200萬年來，人類的“頭顱”是在緩慢變大的，但是“人腦”在近2萬年來卻 “越變越小”，這個殘酷的事實不僅僅發(fā)生在人類身上，科學(xué)家證實腦容量縮小的現(xiàn)象在地球上生活的任何種族的人類群體都有體現(xiàn)。

　　'over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimetres to 1,350 cubic centimetres, losing a chunk the size of a tennis ball,' kathleen mcauliffe writes in discover magazine. 'the female brain has shrunk by about the same proportion.'

　　根據(jù)研究發(fā)現(xiàn)，在過去2萬年來，人類的大腦容量逐漸縮小，平均來說，男性腦容量從1500立方厘米降至1350厘米，也就是相當(dāng)于一個 “網(wǎng)球”大小的腦容量就這么憑空消失了。此外，女性的腦容量縮小的程度與男性“旗鼓相當(dāng)”，難道腦容量縮小，智力會下降嗎？兩者有無直接的關(guān)系呢？

　　some paleontologists agree with this diagnosis, that our brains may have become smaller in size, but increasingly efficient. but others believe that man has indeed become steadily more stupid as he has evolved. several theories have been advanced to explain the mystery of the shrinking brain. one is that big heads were necessary to survive upper paleolithic life, which involved cold, outdoor activities. a second theory is that skulls developed to cope with a chewy diet of rabbits, reindeer, foxes and horses。

　　一些古生物學(xué)者對此持保留態(tài)度，他們認(rèn)為腦容量雖然減少，但是人腦的工作效率仍舊處于逐步增高的狀態(tài)。但是，無論種族、性別，人類腦容量縮小還是一個不爭的事實。部分古生物學(xué)者還是這樣分析腦容量縮小的原因的，他們認(rèn)為在舊石器時代中，古代人類可能需要在復(fù)雜的環(huán)境下生存，比如大量咬嚼大塊食物(野兔、狐貍、馬匹等)、從而直接鍛煉了臉部、甚至腦部的發(fā)達，另外，腦容量越大、適應(yīng)野外寒冷環(huán)境的能力更強。如今，人類的食物愈發(fā)簡單化，不需要很發(fā)達的咬嚼能力，所以腦容量的減少的原因還是有跡可循的。

　　as our food has become easier to eat, so our heads have stopped growing, according to supporters of this theory. other experts say that with high infant mortality, only the toughest survived - and the toughest tended to have big heads. therefore a gradually decreasing infant mortality rate has led to a proportionate decrease in the size of our brains。

　　此外，還有一個理論認(rèn)為，過去嬰兒的死亡率很高，但是依照“適者生存”的道理，頭腦大的嬰兒生命力更強，不會被淘汰，能夠存活下來。而如今的科技發(fā)達，即使腦容量小的嬰兒也能存活。