狗狗可能經常啃壞鞋，偷偷在地毯上撒尿，或者一扭頭就吞掉你的晚餐。可新近研究顯示，狗狗其實比貓咪聰明太多。

美國范德堡大學的研究人員采取客觀測試方法，研究了一些狗狗貓貓的大腦皮質神經元，決心解開到底狗聰明還是貓聰明這個爭論已久的謎題。結果怎樣？原來犬類的大腦皮質神經元比貓科動物多得多。

研究發現，狗擁有約5.3億大腦皮質神經元，貓只有2.5億，不到狗的一半。（人類大腦中皮質神經元數量約為160億。）

范德堡大學心理學與生物學副教授蘇珊娜·赫庫藍諾-赫佐爾與世界各國研究人士合作，共同負責這項研究。她表示：“我認為，動物的神經元、特別是大腦皮質神經元的絕對數量決定了思維豐富程度，以及根據既往經驗預測身處環境的能力。”

這項研究報告將發表在期刊《神經科學前沿》上（美國社交新聞聚合網站reddit的網友肯定會群起而攻之，因為reddit是貓粉大本營）。報告還指出，腦容量和總體智商不一定相關。舉例來說，研究人員發現雖然棕熊的腦容量是貓的十倍，腦神經元數量卻和貓相當。（浣熊的智商也和貓不相上下。）

雖然研究有了結果，但別指望貓狗誰更聰明的爭議會就此打住。赫庫藍諾-赫佐爾也承認，雖然研究是客觀的，她自己就有偏好。

“首先聲明，我絕對是愛狗之人，”她說，“對我來說新發現只是意味著，狗狗比貓咪能做更復雜也更靈活的事而已。”（財富中文網）

譯者：Pessy

審稿：夏林

They might chew your shoes, occasionally pee on the rug, or snarf down your entire dinner the minute you turn your head, but it turns out your family dog is measurably smarter than your cat.

Researchers at Vanderbilt decided to put the age old debate to the test objectively, studying the number of cortical neurons in the brains of a number of animals. The results? Canines had a significantly higher number than felines.

Dogs, it turns out, have about 530 million cortical neurons. Cats have less than half that, coming in with 250 million. (We humans have about 16 billion.)

“I believe the absolute number of neurons an animal has, especially in the cerebral cortex, determines the richness of their internal mental state and their ability to predict what is about to happen in their environment based on past experience,” said Suzana Herculano-Houzel, associate professor of psychology and biological sciences at Vanderbilt, who oversaw the study with a collection of international researchers.

The paper, which will be published in the journal Frontiers in Neuroanatomy (and almost certainly maligned on reddit, the Internet’s haven for cat lovers), notes that the physical size of the brain doesn’t necessarily relate to overall intelligence. For example, researchers found that the brain of a brown bear, while 10 times as large as a cat’s, has roughly the same number of neurons. (Raccoons, also, are on par with cats when it comes to smarts.)

Despite the findings, don’t expect this argument to go away anytime soon. Herculano-Houzel herself admits that, while the study was objective, she herself does have a bit of a bias.

“I’m 100 percent a dog person,” she says, “but, with that disclaimer, our findings mean to me that dogs have the biological capability of doing much more complex and flexible things with their lives than cats can.”