http://www.newyorker.com/science/maria-konnikova/why-are-babies-so-dumb-if-humans-are-so-smart

As aspecies/'spi?iz/, humans are incredibly smart. We tell stories, createmagnificent/m?g’n?f?snt/art andastoundingtechnology, build cities, and explore space.We haven’t been around nearly as long as many other species,but in many respects/r?'sp?kt/we’ve accomplished more than any have before us. We eat them and they don’t eat us. We even run scientific studies on them—and are thinking about re-creating some of those that have goneextinct/?k'st??kt/. But our intelligence comes with acurious/‘kj?r??s/caveat/‘k?v?’?t/: our babies are among thedumbest/d?m/—or, rather/'r?e?/, the most helpless—that exist. A babygiraffe/d??'r?f/can stand within an hour of birth, and can even potentially/p?'t?n??li/flee/fli/predators/'pr?d?t?/on its first day of life. A monkey cangrasp/ɡr?sp/its mother and hang on for protection andnourishment/‘n???m?nt/. A humaninfant/‘?nf?nt/can’t even hold up its own head.

species/‘spi?iz/n. [生物] 物種；種類

magnificent/m?g’n?f?snt/adj.壯麗的, 偉大的, 華麗的, 高貴的

astounding/?’sta?nd??/adj.使人震驚的

extinct/?k’st??kt/adj. 滅絕的，絕種的；熄滅的

curious/‘kj?r??s/adj.好奇的, 好求知的

caveat/‘k?v?’?t/警告凛驮；中止訴訟手續(xù)的申請；貨物出門概不退換中贝；停止支付的廣告

giraff/d??’r?f/長頸鹿

potentially/p?’t?n??li/adv.潛在地;可能地

flee/fli/vi.逃走, 逃掉vt.逃離, 逃避

predator/‘pr?d?t?/n. 食肉動物道宅；掠奪者；捕食者

grasp/ɡr?sp/vt. 抓准取习绢；領(lǐng)會

nourishment/‘n???m?nt/n.食物, 滋養(yǎng)品

infant/‘?nf?nt/n.嬰兒, 幼兒

dumb/d?m/adj. 啞的，無說話能力的蝙昙；不說話的闪萄，無聲音的

The evolution/?iv?'lu??n/of human intelligence isn’t something thatCeleste Kiddhad everpondered/'pɑnd?/. A developmentalcognitive/'kɑɡn?t?v/scientist who currently works at the University ofRochester, her work had focussed mostly on learning and decision-making in children. Over years of observing young children, she became?impressed with the average child’s level ofsophistication/s?,f?st?'ke??n/. But when she looked at the infants she encountered, she saw abaffling/'b?fl??/degree of helplessness: How could they be soincompetent/?n'kɑmp?t?nt/one second and so bright so soonthereafter/?e?r'?ft?/? One day, she posed/poz/the question to her colleague Steven Piantadosi. “Both of us wondered what could possibly justify/'d??st?'fai/the degree of helplessness human infants exhibit/?ɡ'z?b?t/,” she told me recently. “Even otherprimate/'pra?met/babies, like babychimps/t??mp/, which are closein evolutionary/?iv?’lu??n?ri/terms, cancling/kl??/onto their moms.” She began to see acontradiction/?kɑntr?'d?k??n/: humans are born quite helpless,far moreso than any other primate, but,fairly early on, we start becoming quite smart, again far more so than any other primate. What if this weren’t a contradiction so much as acausal/‘k?zl/pathway?

sophistication/s?,f?st?’ke??n/復雜；詭辯奇颠；老于世故败去；有教養(yǎng)

evolution/?iv?’lu??n/演變；進化論烈拒；進展

ponder/‘pɑnd?/vi. 沉思圆裕；考慮

cognitive/‘kɑɡn?t?v/adj.認知的, 認識能力的

baffling/‘b?fl??/adj. 令人困惑的；阻礙的荆几；令人喪氣的吓妆；變幻的

helplessness/?h ?lpl?sn?s/n.無可奈何狀態(tài);無能為力

incompetent/?n’kɑmp?t?nt/adj.無能力的, 不稱職的, 不勝任的

thereafter/?e?r’?ft?/adv.此后; 在那之后

pose/poz/提出 (問題)[正式]

justify/‘d??st?’fai/vt.證明…有理; 為…辯護

primate/‘pra?met/adj. 靈長目動物的

chimp/t??mp/n. （非洲的）黑猩猩

evolutionary/?iv?’lu??n?ri/adj.進化的

cling/kl??/vi. 堅持，墨守吨铸；緊貼行拢；附著

cling onto緊緊抓住

contradiction/?kɑntr?’d?k??n/n.矛盾

causal/‘k?zl/adj. 有原因的；因果關(guān)系的

exhibit/?ɡ’z?b?t/展覽焊傅；顯示剂陡；提出（證據(jù)等）

fairly early on相當早

That’s the argument/'ɑrɡjum?nt/that Kidd and Piantadosi make in theirnew paper, published in a June issue ofPNAS.Humans become so intelligentbecausehuman infants are so incredibly/?n'kr?d?bli/helpless, they argue; the onenecessitates/n?’s?s?tet/the other. The theory isstartling/'stɑrtl??/, but it isn’t entirely new. Researchers have been pondering thepeculiarities/p?'kj?l?'?r?ti/of our birth and its evolutionary/?iv?'lu??n?ri/significance/s?ɡ'n?f?k?ns/for quite some time. Humans belong to the subset of mammals/‘m?ml/, called?viviparous/v?'v?p?r?s/mammals, that give live birth to their young. This means that infants must grow to a mature/m?'t??r/enough state inside the body to be born, but they can’t be so big that they are unable to come out. This leads to a trade-off/?tred??f/: the more intelligent an animal is, the larger its head generally is, but the birth canal/k?'n?l/imposes/?m’poz/an upper limit on just how large that head can be before it gets stuck/st?k/. The brain, therefore, must keep maturing, and the head must continue growing, long after birth. The more intelligent an animal will eventually be, the more relatively immature/??m?'t??r/its brain is at birth.

argument/‘ɑrɡjum?nt/論證；論據(jù)狐胎；爭吵鸭栖；內(nèi)容提要 n

incredibly/?n’kr?d?bli/

necessitates/n?’s?s?tet/vt. 使成為必需，需要握巢；迫使

startling/‘stɑrtl??/adj. 令人吃驚的

peculiarities/p?’kj?l?'?r?ti/特性晕鹊；特質(zhì)；怪癖暴浦；奇特

viviparous/p?’kj?l?’?r?ti/adj. [脊椎] 胎生的溅话；在母體上發(fā)芽的

significance/s?ɡ’n?f?k?ns/n. 意義；重要性歌焦；意思

mature/m?’t??r/adj. 成熟的飞几；充分考慮的；到期的独撇；成年人的

Researchers have long known about this trade-off, and about theconnectionbetween brain size andneural density/'d?ns?ti/and intelligence.For instance, Robin Dunbarfoundthat the ratio ofneocorticalvolume to brain size can predict the social-group sizein a number ofspecies, includingbats/b?ts/,cetaceans, and primates, whileSimon Readerhasdemonstrated/‘d?m?n'stret/links in tool use and innovation/??n?'ve??n/to brain size in primates. Kidd and Piantadosi’s new idea is that increased helplessness in newborns mandates/'m?ndet/increased intelligence in parents—and that arunaway/'r?n?we/selection dynamic can account for both.Natural/'n?t?r?l/selectionfavorshumans with large brains, because those humans tend to be smarter. This may create evolutionaryincentivesfor babies that are born at an even earlier developmental stage, which require more intelligence to raise. This creates the dynamic: over time, helpless babies make parents more intelligent, which makes babies more helpless, which makes their parents more intelligent, and so on.

neuraladj. 神經(jīng)的屑墨；神經(jīng)系統(tǒng)的躁锁；背的；神經(jīng)中樞的

density/‘d?ns?ti/n. 密度

neocortical?ni?o?’k??rteks[解]新(大腦) 皮質(zhì)

in a number of ways:在許多方面

bat/b?ts/蝙蝠卵史；球棒战转；球拍；批處理文件的擴展名

cetacean/s?’te??n/adj. 鯨類的以躯；鯨魚的 | n. 鯨魚槐秧；鯨類動物

primates/prai'meiti:z/靈長類

demonstrate/‘d?m?n’stret/vt. 證明；展示忧设；論證

mandate/‘m?ndet/n.授權(quán)刁标；命令，指令见转；委托管理命雀；受命進行的工作vt. 授權(quán)蒜哀；托管

runaway/‘r?n?we/adj. 逃亡的斩箫；逃走的 |n. 逃跑；逃走的人

developmental stage 發(fā)育階段

incentive/?n’s?nt?v/n. 動機撵儿；刺激 |adj. 激勵的乘客；刺激的

dynamic/da?’n?m?k/adj. 動態(tài)的；動力的淀歇；動力學的易核；有活力的

Natural/'n?t?r?l/selection 自然選擇

Over time隨著時間的過去；超時

During their investigation, Kidd and Piantadosi realized something important that strengthened/'str??θn/their theory. It turns out that another variable/'v?r??bl/has an even highercorrelation/?k?r?'le??n/with intelligence than brain size—time tomaturity/m?'t??r?ti/, orweaningtime.In other words, the time it takes toshepherd/???p?d/newborns/?nju??b??n/through absolute helplessness to a point of relativeself-sufficiency/'selfs?'fi??nsi/predicts primate intelligence more strongly than the best measure that has?previously beenproposed/pr?u'p?uzd/, namely, headcircumference. Orangutans/??r??'?t?n/have smarter babies thanbaboons/b?'bu:n/and theyweanthem longer. Baboon babies, in turn, are weaned longer, and are smarter, thanlemur/?lim?/babies.

strengthen/‘str??θn/vt. 加強浪默；鞏固

correlation/?k?r?’le??n/n. [數(shù)] 相關(guān)牡直，關(guān)聯(lián)；相互關(guān)系

maturity/m?’t??r?ti/n. 成熟纳决；到期碰逸；完備

weaning/'wi:ni?/adj. 斷奶的

shepherd/???p?d/vt牧羊；帶領(lǐng)阔加；指導饵史；看管 ?|牧羊人；牧師胜榔；指導者

self-sufficiency/‘selfs?’fi??nsi/n. 自給自足胳喷；自負

proposed/pr?u’p?uzd/adj. 被提議的；所推薦的

circumference/s?’k?mf?r?ns/圓周夭织；周長吭露；胸圍

orangutan/??r??’?t?n/[脊椎] 猩猩（等于orangoutang）

baboon/b?'bu:n/[脊椎] 狒狒

lemur/?lim?/[脊椎] 狐猴

Putting these facts together helped Kidd and Piantadosi develop theirhypothesis/ha?'pɑθ?s?s/.The connection between head size and intelligence does create incentives for babies to arrive earlier. But it’s the connection between weaning time and intelligence that may really be driving/'dra?v??/the cycle/'sa?kl/. You need to be smarter to care for more helpless creatures, which means you need a larger brain—which means that babies have to enter the world at an even more helpless stage of development, since there is afinitesize to their brain at birth, mandated by thephysiologyof live birth. And so the cycle continues.

hypothesis/ha?’pɑθ?s?s/假設(shè)

drivingvt. 推動，發(fā)動（機器等）尊惰；駕駛（馬車讲竿，汽車等）纬向；驅(qū)趕

the cycle/‘sa?kl/周期

Of course, the theory is just that—a model.Ideally/a?'di?li/, to prove it you would look at head size, birth time, and intelligence over the span of human evolution, to see if we were born earlier as we got smarter—data that areunavailable/'?n?'vel?bl/. (Kidd alsostresses/str?s/repeatedly that this theorysupplements/'s?pl?m?nt/, but does notsupplant/s?'pl?nt/, earlier ones: it cancoexist/?ko?ɡ'z?st/quite naturally with both the social-groupaccount ofintelligence—the Dunbar/'d?nbɑ:/approach—and what’s called themetabolic/?m?t?'bɑl?k/accounts of intelligence, whichposits/‘pɑz?t/that ourdigestive/da?’d??st?v/system hasallowedfor our brain’s highmetabolicneeds, and that we grew smarter to be able to find and sharedifficult-to-gatherfood.) But there are someintriguing/?n?tri:g??/converging/k?n'v?:d?i?/pieces of evidence. For one, other animals that arenotviviparous/v?'v?p?r?s/have not evolved the same levels of intelligence, suggesting aninherent/?n'h?r?nt/link between live birth andbrainpower/?bren?pa??/. And in modern humans, a few pieces of evidence appear to suggest that smarter parents are more likely to have offspring that survive. Inone limited sample/'s?mpl/—two hundred and twenty-two Serbian/'s?:bi?n/Roma/'r?m?/women—maternal/m?’t?nl/I.Q. and childmortality/m?r’t?l?ti/were negatively correlated (that is, higher I.Q. meant lowermortality), even controlling for education, age, and a number of other factors. In alarger sampleof Californian parents, in 1978, years of education were linked to infant-mortality rates. Globalepidemiologicalstudiessuggest/s?'d??st/a decrease in mortality that equals between seven and nine per cent for each year of a mother’s education. None of this isdecisive, of course, but it is suggestive.

unavailable/‘?n?’vel?bl/難以獲得的；不能利用的戴卜；不近便的

stress/str?s/強調(diào)逾条；使緊張；加壓力于投剥；用重音讀

supplement/‘s?pl?m?nt/增補师脂，補充；補充物江锨；增刊吃警，副刊

supplant/s?'pl?nt/代替；排擠掉

coexist/?ko?ɡ’z?st/共存啄育；和平共處vi

metabolic/?m?t?’bɑl?k/變化的酌心；新陳代謝的

posit/‘pɑz?t/vt. 安置；假定

digestive/da?’d??st?v/消化的挑豌；助消化的

intriguing/?n?tri:g??/有趣的安券；迷人的

converging/k?n'v?:d?i?/adj. 會聚的，收斂

brainpower/?bren?pa??/智能氓英；智囊團

maternal/m?'t?nl/母親的侯勉；母性的；母系的铝阐；母體遺傳的

mortality/m?r’t?l?ti/死亡數(shù)址貌，死亡率；必死性徘键，必死的命運

link to把…和…聯(lián)系起來

suggest/s?’d??st/vt提議练对，建議；啟發(fā)吹害；使人想起螟凭；顯示；暗示

epidemiologicalhttps://en.wikipedia.org/wiki/Epidemiology[?ep??di?mi?’l?d??kl] 流行病的

epidemiology[?ep??di?mi’ɑ?l?d?i]傳染病學赠制；流行病學

Epidemiologyis the study and analysis of thepatterns,causes, and effects ofhealthanddiseaseconditionsin definedpopulations.

decisive/d?’sa?s?v/. 決定性的赂摆；果斷的，堅定的

suggestive/s?’d??st?v/提示的钟些，示意的烟号；暗示的；引起聯(lián)想的

There is, of course, one follow-up question: Why did this cycle/'sa?kl/happen to humans and not tolemurs?When I asked Kidd about this, she told me that their theory cannot offer an answer—likely as not, it’s a matter of pure genetic/d??’n?t?k/luck that became self-reinforcing. As we grew smarter, we were better able to take care of our infants, so they could be born more helpless and allow us to grow even smarter.

likely as not

as likely as not:很可能政恍；多半汪拥；說不定

genetic/d??’n?t?k/遺傳的；基因的篙耗；起源的

self-reinforcing/?ri?n’f?rs/vt. 加強迫筑，加固宪赶；強化；補充

One intriguing way to test the hypothesis/ha?'pɑθ?s?s/further: look at twins. Typically/'t?p?kli/,twins are not carried to full term/t?m/.Does that mean that twins are more intelligent than non-twins, since they require longer weaning time—and would a mother who is a twin, in turn, give birth to smarter children? “It’s a really good question, to look at the types of twins that run in families and whether that leads to higher intelligence,” Kidd said. “It’s a predictable/pr?'d?kt?bl/hypothesis,” and one that they may well include in their ongoing research on trainheritability/?herit?'bil?ti/in twins. And it’s a hypothesis that came, of all places, from a five-year-old—Kidd was being interviewed about twins for apodcast/p?d'k?st/by the daughter of Sindya Bhanoo, a formercolumnist/'kɑl?mn?st/at theTimes. Dumb babies, maybe, but oh so smart, oh so soon thereafter.

typically/‘t?p?kli/adv. 代表性地脯燃；作為特色地

term/t?m/術(shù)語搂妻；學期；期限辕棚；條款欲主；(代數(shù)式等的)項

predictable/pr?’d?kt?bl/可預言的

heritability/?herit?’bil?ti/遺傳可能性

podcast/p?d’k?st/播客

columnist/‘kɑl?mn?st/專欄作家

Maria Konnikova is acontributing/k?n’tr?bjut/?writer for?newyorker.com, where she?writes?regularly?on?psychology/sa?’kɑl?d?i/?and science.

contribute/k?n’tr?bjut/投稿

psychology/sa?’kɑl?d?i/心理學；心理狀態(tài)?