美國總統奧巴馬在2016年新年獻詞中誓言，將在2016年解決槍械暴力問題，并決定新年第一天開工就召見司法部長洛麗塔?林奇，討論如何繞過國會來應對槍械暴力這個棘手問題。

實際上，2015年12月，圣貝納迪諾槍擊案發生之后，人們就開始從不同的角度對它進行解讀。有些人在談控槍法案，有些人在談伊斯蘭恐怖主義，還有人在談精神健康問題。不管此次槍擊案到底是什么原因引起的，有一件事是明顯的。那就是，不管是保守主義者還是自由主義者，每個人都在為死難者感到悲痛。沒有人希望類似的悲劇重演。

不幸的是，美國遭受另一次大規模的槍擊事件只是時間早晚的問題。目前，美國還無法就旨在解決此類槍擊事件的政策形成共識。如果你想知道為什么，就請仔細看看下面這張圖。

People are explaining the San Bernardino massacre in different ways. Some people say it is about gun laws. Others say it is about Islamic terrorism or mental health. Whatever the case, one thing is clear: Everyone, conservatives and liberals alike, grieved for the victims. No one wants such a thing to happen again.

Sadly, it’s only a matter of time before the United States suffers another mass shooting. For now, the country just can’t agree on a policy to address such shootings. And if you want to understand why, take a careful look at the image that accompanies this article.

這張圖片是圣貝納迪諾槍擊案發生幾小時后，由紐約Betaworks公司的數據科學家繪制的。圖中各種顏色的點（或者說節點）代表了社交網站Twitter上的用戶賬號。最重要的是，它展示了有關此次槍擊案的消息和評論是怎樣在三大用戶群體間傳播的。這三個群體分別是“為憲法第二修正案辯護者”（藍點）、“槍械與狩獵愛好者”（紫點）和“槍支安全呼吁者”（紅點）。

從圖片中可以看出，在槍擊案發生后，這三個群體的行為都有過強烈的爆發，他們分別開始在各自的“社交圖譜”里傳播關于槍擊案的消息（“社交圖譜”一詞主要用來形容任何一種社交媒體的關系鏈）。在每個群體中，都有一些節點扮演了信息的超級傳播者。根據Betaworks公司的數據顯示，這三個群體中最搶眼的信息傳播者分別是@Trident_Arms、@ConcealnNCarrynt和@Bradybuzz。

我們可以看出，這三個群體都傾向于在群體內部傳遞信息。其中，藍色和紫色兩個群體也會互相分享信息，但它們與紅色群體之間幾乎沒有任何信息交流。換句話說，人們很大程度上只與已經跟自己持有相同觀點的人交流信息。也就是說，支持控槍的人只和志同道合者聊天，支持《第二修正案》的人也只和支持擁槍自衛的人聊天。

Betaworks公司首席數據科學家吉拉德?洛坦指出：“這張圖代表了兩個兩極分化的獨立網絡，而且它們之間是沒有相互交流的。”洛坦上周在哥倫比亞大學新聞研究院發布了這張圖片。人們只和與自己看法類似的人交流這種現象（又稱“趨同性”或“過濾泡沫”現象）并不新鮮，不過洛坦表示，這種現象已經變得比以往更加嚴重。

“最終，它反映的是我們這個社會，反映的是我們非常丑陋的一面。”洛坦說。（財富中文網）

譯者：樸成奎

審校：任文科

The image was created in the hours after San Bernardino by data scientists at a company calledBetaworks in New York City. It is composed of a series of dots, or nodes, that represent different accounts on the social media site Twitter TWTR 2.17% . Most importantly, it shows how news and comments about the shooting spread among three clusters of users, labeled here as “Second Amendment Defenders” (the blue dots), “Firearms and Hunting” (the purple dots) and “Gun Safety Advocates” (the red dots).

The image shows how there was an intense burst of activity among the respective clusters as people spread news of the shooting within their “social graph,” a term that describes the chain of relationships in any social media system. And within each cluster, there were some nodes that act as information super-vectors. Betaworks identified the most significant, in terms of each group, as Trident Arms, Conceal&CarryNetwork and Brady Campaign.

As you can see, each of the three groups shared information internally. Two of the groups—the purple and blue ones—passed news between their respective networks but shared almost zero with those in the red group. In other words, people largely exchanged information with those who already shared the same views: Gun control people talked to like-minded people, and the Second Amendment people did the same.

“It represents two extremely polarized and separate networks that are not talking to each other,” said Gilad Lotan, chief data scientists at Betaworks, who presented the graphic last week at Columbia University Graduate School of Journalism. This phenomenon of people talking only to like-minded individuals (known as “homophily” or “filter bubbles”) is not new, but Lotan says it is getting far more intense.

“In the long run, it’s kind of reflecting our society back at us. It’s reflecting a very ugly mirror at us,” said Lotan.