Some doubt might be cast on the general validity of the results by the following brief description of the experiment being reported here:
"In the study, 40 wallets were sent out in each photograph category as well as 40 containing a card suggesting that the owner had recently made a contribution to charity. A control batch contained no additional item.
All of the wallets were stuffed with the same set of everyday items, including raffle tickets, discount vouchers, and membership cards. None of them contained money, however."
"In the study, 40 wallets were sent out in each photograph category as well as 40 containing a card suggesting that the owner had recently made a contribution to charity. A control batch contained no additional item.
All of the wallets were stuffed with the same set of everyday items, including raffle tickets, discount vouchers, and membership cards. None of them contained money, however."
(Added italics mine.)