良いことをした後は利己的になる (New York Times)

環境に良いものを買うなど、
社会にとって良いことをした後は、
もうこれで十分だろうと思って、
より利己的になる、という話。

"When ‘Green’ Consumers Decide,‘ I’ve Done Enough’
http://www.nytimes.com/2010/03/22/business/energy-environment/22green.html

• 156 volunteers were placed in front of computers where they were exposed at random either to an online shop offering mostly eco-friendly products or to one offering mostly conventional goods. Some shoppers in each group were asked to rate the products only on “aesthetics of design” and the “informativeness” of their description. The rest were invited to make purchases.
• All participants were then asked to engage in a seemingly unrelated exercise that involved sharing money.
• Those who had simply been exposed to the “green” store — that is, those who had merely rated the products — shared the most money.
• Those who had purchased products at the green store were easily the least generous.
• those participants who perceived themselves as having already done their bit for the world by purchasing green products felt no particular obligation to be benevolent afterward.

さらに、Green storeで買った人とConventional storeで買った人に、
その後、PC上で問題を解いてもらって正解した分支払う、というTaskを与えて、
でも実際は、PC画面上に表示される支払い金額は、正解不正解にかかわらず増えていく、という風にプログラムされている実験を行った場合、
Green storeで買った人の方が、正確に答えようとせずとにかくボタンを押してたくさん問題をこなしてお金を得ようとしていたらしい。