We humans have the ability to learn, to reason and solve problems. We're self-aware, and we’re also conscious of the presence, thoughts and feelings of others. We make tools and practice the art of deception. We're creative. We think abstractly. We have language and use it to express complex ideas. All of these are arguably signs of intelligence. Scientists may not agree on the best and fullest definition of intelligence – but they generally agree that humans are highly intelligent.

Other members of the animal kingdom exhibit signs of intelligence as well, and some scientists might say the definition of animal vs. human intelligence is merely a matter of degree – a point that was brought home in 2005 when the London Zoo put “Homo sapiens” on display in the exhibit pictured here. Click the "Next" arrow above to learn about nine other species that stand out for their smarts.

Chimps are almost like us

If we humans possess intelligence, chimpanzees must have some as well: Our genomes are at least 98 percent identical. Chimps make and use tools, hunt in organized groups and engage in acts of violence. Wild troops have distinct behaviors and customs. Field observations and lab experiments show chimps are capable of empathy, altruism and self-awareness. In the experiment pictured here, chimps performed better than humans on a number memory test.

Dolphins get creative

This dolphin in Australia uses a sponge to protect her snout when foraging on the seafloor, a tool use behavior that is passed on from mother to daughter. Scientists say that’s just one sign of dolphin smarts. Other signs include distinct whistles and clicks that may serve as dolphin names, perhaps used in a type of language. A famous 1960s experiment found that a pair of dolphins entered a tizzy of creativity once they figured out their novel behaviors were rewarded with fish. Frustrated human test subjects just let out a sigh of relief when they caught on to the idea.

Elephants exhibit self-awareness

The sheer size of their brains suggests that elephants must know a thing or two about the ways of the world. They have been seen consoling family members, helping other species in times of need, playing in water and communicating with one another via vibrations sensed in their feet. A crowning achievement, some researchers say, was when this female Asian elephant named Happy recognized herself in the mirror. The complex behavior is shared only with humans, great apes and dolphins.

Cephalopods have big brains

Are octopi, squids and cuttlefish smart? That’s a matter of scientific intrigue, but such cephalopods are certainly among the brainiest invertebrates in the sea. The cephalopod brain surrounds the esophagus, but shares with the human brain features of complexity such as folded lobes and distinct regions for processing visual and tactile information. The how-smart debate swirls around deciphering observations that the creatures have a seemingly irrepressible curiosity, a disdain for boredom, an ability to learn and the capacity to use tools. The octopus pictured here exerts precise muscle control to eat.

Crows get crafty

Crows are crafty critters: They fashion tools from twigs, feathers and other bits of debris to snare food from hard-to-reach places. A crow named Betty, pictured here, uses a straight wire she bent into a hook to retrieve food from a tube. The birds are born with a tool-making ethic, but they hone their craft by watching their elders, a sign of higher intelligence. Ravens, a type of crow, have even been shown to manipulate the outcomes of their social interactions for added protection and more food.

Squirrels can be deceptive

Is the squirrel pictured here plotting deception? Perhaps. Researchers recently reported that the rodents put on elaborate shows of deceptive caching to thwart would-be thieves. The behavior increased in a lab experiment after squirrels observed humans stealing their peanuts. The researchers called the finding a sign that squirrels can interpret intentions of others, though it could just be a case of learned behavior. Other studies have shown the critters make three-dimensional maps to recall where they cache their nuts. And squirrels in California will cover their fur in the scent of rattlesnakes to mask their own scent from predators.

Man's best friend

Are dogs intelligent or just really good at basic obedience? They can learn to sit, lie down and fetch, for example, but can they read their owner's intentions? Research suggests they can at least find food in response to non-verbal cues, a type of understanding that scientists think may be akin to the human ability to understand someone else's point of view. The dog in the experiment pictured here accurately discriminated between photos of dogs and photos of landscapes – an indication the dog was able to form the concept of "dog."

Cats are adaptable

Like dog owners, some cat owners have trained their pets to sit down, roll over and jump through hoops. Cats learn the tricks by observation and imitation, egged on with positive reinforcement. But training cats is harder than dogs. Does that mean they are less intelligent? Not necessarily. Cat experts say felines are just different. They are solitary animals, motivated by the need to survive. This has allowed them to adapt to a variety of domestic environments for at least 9,500 years – even the hoods of cars.

Pigs are wise - and clean

Here's the dirt on pigs: They are perhaps the smartest, cleanest domestic animals known – more so than cats and dogs, according to some experts. But pigs don't have sweat glands, so they roll around in the mud to stay cool. A sign of their cleverness came from experiments in the 1990s. Pigs were trained to move a cursor on a video screen with their snouts and used the cursor to distinguish between scribbles they knew and those they were seeing for the first time. They learned the task as quickly as chimpanzees.

我們?nèi)祟愑袑W(xué)習(xí)、找出問(wèn)題的原因并解決問(wèn)題的能力。我們?nèi)祟愂怯凶灾�之明的，并且我們也存在意識(shí)，思想，對(duì)其他事物有感知。我們有語(yǔ)言并使用它去表達(dá)復(fù)雜的思想。所有的這些都是聰明的標(biāo)志�？茖W(xué)家也許不同意聰明的最好、最完全的定義，但是他們通常贊成人類是聰明的。

在動(dòng)物的王國(guó)里的其他成員也存在著聰明的標(biāo)記，一些科學(xué)家也許會(huì)說(shuō)動(dòng)物以及人類的聰明的定義僅僅是一個(gè)程度上的問(wèn)題，2005年當(dāng)倫敦動(dòng)物園展覽了”智人”圖片時(shí)被認(rèn)識(shí)清除了。點(diǎn)擊上面的”下一個(gè)”箭頭了解其他的九種因?yàn)槁斆鞫�出眾的�?dòng)物。

黑猩猩和我們十分相像

如果我們?nèi)祟悡碛兄橇Γ�那么黑猩猩一定也有一些智慧：因�(yàn)槲覀兊娜旧�體組98%以上是一樣的。黑猩猩制造并使用工具，有組織的打獵并且參加暴力行動(dòng)。野生黑猩猩群體有獨(dú)特的行為和習(xí)慣。野外觀察和實(shí)驗(yàn)室試驗(yàn)表明，黑猩猩有移情、利他和自我意識(shí)的能力。在這個(gè)被描述的試驗(yàn)中，黑猩猩在一系列的記憶力測(cè)試中表現(xiàn)好于人類。

海豚有創(chuàng)造力

這只澳大利亞的海豚當(dāng)在海底覓食時(shí)用一個(gè)海綿保護(hù)她的嘴，這是從海豚媽媽傳給海豚女兒的一個(gè)使用工具的行為�？茖W(xué)家說(shuō)這只是海豚聰明的標(biāo)志之一。其他的標(biāo)志包括獨(dú)特的口哨和敲擊也許會(huì)作為海豚的名字，也許在一種語(yǔ)言中使用。二十世紀(jì)60年的一個(gè)著名的試驗(yàn)發(fā)現(xiàn)，一旦海豚領(lǐng)會(huì)到他們因?yàn)樽龀鲂缕娴膭?dòng)作而被獎(jiǎng)勵(lì)魚(yú)后，一對(duì)海豚因創(chuàng)造而激動(dòng)興奮。當(dāng)他們理解了這個(gè)意思時(shí)致使人類的測(cè)試項(xiàng)目失敗只是因減緩而嘆口氣。

大象存在自我意識(shí)

大象的大腦暗示大象一定知道世界上的一兩件事情。他們被認(rèn)為可以安慰家族成員，在其他動(dòng)物需要幫組時(shí)給予幫助，在水中玩耍，以及通過(guò)他們腳感覺(jué)的震動(dòng)感來(lái)與同類交流。一些研究人員說(shuō)，當(dāng)一只叫“快樂(lè)”的亞洲母象在鏡子中認(rèn)識(shí)自己時(shí)是一個(gè)最高的成就。復(fù)雜的行為僅與人類，黑猩猩和海豚共有。

頭足類動(dòng)物有很大的大腦

章魚(yú)、魷魚(yú)以及烏賊有智力嗎？這是一個(gè)科學(xué)疑點(diǎn)，但是這些頭足類動(dòng)物都是大海中的最聰明的無(wú)脊椎動(dòng)物。頭足類動(dòng)物的大腦圍繞著食道，但是和人類大腦一樣復(fù)雜，例如折疊的圓突和處理視覺(jué)和觸覺(jué)信息的獨(dú)特區(qū)域。頭足類動(dòng)物有多聰明的辯論圍繞著譯碼觀察—這些生物有表面的抑制不住的好奇心、對(duì)厭倦蔑視、有學(xué)習(xí)的能力并且有使用工具的能力。章魚(yú)被認(rèn)為有專門的肌肉控制進(jìn)食。

烏鴉很狡猾

烏鴉是很狡猾的生物：他們將嫩枝、羽毛以及其他的小塊的碎片改造成工具在他們接觸不到的地方誘捕食物。一個(gè)叫貝蒂的烏鴉，將一根直的電線彎成鉤狀在一根管子里找回食物。烏鴉生來(lái)就是一個(gè)工具制造家，但是他們通過(guò)觀察老烏鴉學(xué)會(huì)手藝，這是一個(gè)烏鴉有較高的智力的標(biāo)志。烏鴉的一種—­—大烏鴉，甚至顯示出利用他們的群居相互接觸的成果增加保護(hù)并獲得更多的食物。

松鼠是靠不住的

在這里描述的松鼠耍詭計(jì)？也許。最近研究人員報(bào)告說(shuō)，嚙齒動(dòng)物的像小偷一樣的貯藏行為詳細(xì)的表明了他們的欺騙性。在一個(gè)實(shí)驗(yàn)室試驗(yàn)中，松鼠觀察人類后偷人類花生這種行為增多了。盡管這一行為可能僅僅是一個(gè)學(xué)習(xí)行為的例子，研究人員稱這一發(fā)現(xiàn)為松鼠能解釋其他物種的意圖的一個(gè)標(biāo)志。其他的研究表明嚙齒動(dòng)物繪制三維地圖來(lái)記住他們儲(chǔ)存堅(jiān)果的地點(diǎn)。并且在加利福尼亞松鼠將使自己的皮毛沾染響尾蛇的氣味來(lái)掩蓋自己本身的氣味以逃避天敵。

人類最好的朋友

狗是聰明的還是僅僅是擅長(zhǎng)于基本的服從？例如他們能學(xué)會(huì)坐著，躺下和取物，但是他們能不能讀懂他們的主人的意圖？研究表明他們至少可以響應(yīng)找食物的暗示，也就是理解的一種，科學(xué)家認(rèn)為也許就像是人類理解某人的角度的觀點(diǎn)。在這個(gè)試驗(yàn)中描述的狗準(zhǔn)確的區(qū)分了狗的照片和風(fēng)景的照片——這是一種狗能形成“狗”的概念的跡象。

貓的適應(yīng)性

和一些狗的主人一樣，一些貓的主人曾經(jīng)訓(xùn)練他們的寵物坐下，打滾以及跳圈。貓學(xué)習(xí)通過(guò)觀察和模仿學(xué)習(xí)這些花招，正強(qiáng)化的被慫恿。但是訓(xùn)練貓要比訓(xùn)練狗難。這是不是意味著貓比狗笨?不盡然。貓的研究專家說(shuō)貓科動(dòng)物是不同的，他們是孤獨(dú)的動(dòng)物，由生存的需求推動(dòng)。這使得他們適應(yīng)各種家庭馴養(yǎng)的環(huán)境甚至有蓬汽車至少9,500年。

豬既有智慧還愛(ài)干凈

這是有關(guān)豬的流言：據(jù)一些專家稱，豬也許是最聰明最干凈的已知的馴養(yǎng)動(dòng)物。甚至與貓和狗相比。但是豬沒(méi)有汗腺，所以他們?cè)谖勰嘀写驖L來(lái)保持涼爽。二十世紀(jì)九十年代的實(shí)驗(yàn)證明豬很聰明。豬被訓(xùn)練用他們的嘴移動(dòng)電視屏幕上的指針，并用這個(gè)指針辨別他們認(rèn)識(shí)的涂鴉和他們第一次見(jiàn)到的涂鴉。豬像黑猩猩一樣快速的完成了這個(gè)任務(wù)