研究表明 健康行爲也會像疾病一樣傳染大綱

If your friends are happy—turns out you're more likely to be happy too. If your friends are overweight, that too ups the odds you'll pack on pounds.

如果你的朋友很快樂，那你也快樂的可能性很大。如果你的朋友體重超重，那你體重增加的機率也會上升。

Those effects have been shown in studies. And now researchers have identified another seemingly contagious quality: exercise.

這些效應已經被研究證明。現在，研究人員證實了另一個似乎具傳染性的東西：鍛鍊。

The investigators analyzed the running activity of more than a million individuals worldwide who used an exercise tracking device for five years. And they used weather patterns as a way to randomly examine different parts of that global network.

研究人員分析了全球100多萬人的跑步活動，這些人5年來一直在使用運動追蹤裝置。研究人員運用天氣模式對全球不同地區進行隨機檢測。

"If it happens to be a really nice day out, sunny and not too hot, not too cool, that will induce people to run more." Sinan Aral, a computational social scientist at MIT. "If it's a rainy day and cold, that will induce people to stay in more on average."

麻省理工學院的計算社會科學家希南·阿拉爾表示：“如果趕上好天氣，陽光明媚，溫度適中，那外出跑步的人會更多。但是如果是下雨天，而且很陰冷，那人們更願意呆在家裏。”

And since different cities have different weather patterns, he says, this natural experiment allowed them to ask: Does a rainy day in New York affect running in San Diego?

阿拉爾表示，由於不同的城市有不同的天氣模式，自然實驗使研究人員產生這樣的問題：紐約下雨會影響聖地亞哥的跑步活動嗎？

"If the weather in New York causes changes in the running behavior in San Diego, it can really only be happening thru peer influences of the friends who live between New York and San Diego."

“如果紐約的天氣可以改變聖地亞哥的跑步行爲，這隻能通過居住在紐約和聖地亞哥的朋友之間的同伴影響產生。”

And that is exactly what he and his colleague saw: that the behavior of one city's runners could indeed affect the behavior of runners in another socially connected city. The study is in the journal Nature Communications.

這就是阿拉爾和同事們得出的結論：一個城市跑步者的行爲可能的確會影響與其有社交聯繫的另一個城市跑步者的行爲。這項研究結果發表在《自然通訊》期刊上。

A few caveats: women tended to be influenced more by the female runners in their networks. And less active runners tended to influence more active runners to run more, but not so much the other way around. Still, this could be valuable intel for health professionals.

幾點說明：女性更容易受其社交圈中的女性跑步者的影響。活躍度低的跑步者會令活躍度高的跑步者增加跑步距離，但後者對前者的影響卻不太多。不過，這對健康專家來說可能仍是個有價值的情報。

"We have to start thinking about consumers and citizens as networked consumers and networked citizens. Where they are influenced by and influence their social network in very strong and dynamic ways, that will change the way a particular intervention succeeds or fails."

“我們要開始將用戶和市民看作網絡化的用戶和市民。因爲他們會以非常強烈又動態的方式影響其社交網絡，或被社交網絡影響，而這會改變特殊干涉的成敗。”

In other words -- if your prescription is more exercise? The doctors might want to write a prescription for your friends and family, too.

換而言之，如果你的處方是增加鍛鍊，那醫生或許想讓你的朋友和家人也多運動運動。