He discovered that people were more likely to buy energy efficient light bulbs from the shops, but tended to opt for the old-fashioned type online。

　　他发现，在商店里，人们会购买节能灯泡，但在网上购物时，人们就会选择老式灯泡。

　　"Many green purchases are rooted in the evolutionary idea of competitive altruism, the notion that people compete forstatus by trying to appear more altruistic," he said。

　　“绿色购物的习惯其实根植于宣扬公德心而导致的攀比，人们以此作为显示地位的方式。”

　　Mr Griskevicius picks out the Toyota Prius car as a prime example. Celebrities including Leonardo DiCaprio and Cameron Diaz have been photographed behind the wheel of a Prius, despite being well able to afford a more powerful and expensive car, sending the message that they are concerned for the environment。

　　Griskevicius教授以丰田普锐斯为例：莱昂纳多·迪卡普里奥和卡梅伦·迪亚兹这样的明星都曾拍过站在丰田普锐斯旁边的照片，虽然他们完全有能力支付更昂贵的的汽车，然而选择丰田普锐斯不过是为了向公众宣告他们很关心环境问题。

　　The study also showed that people were often more willing to buy green products when they were the most expensive option, because it showed they could afford to be caring。

　　研究也发现，人们更愿意购买价格昂贵的绿色产品，体现他们有一定经济能力来保护环境。

　　While shoppers are more likely to buy environmentally friendly products on the high street where they can be seen to make the selfless choice, but behind closed doors it is a different matter。

　　当大庭广众下的购物者更倾向于购买绿色产品以体现无私精神时，关上家门在网上购物就是另一回事了。