Committing a small act of kindness, like holding the door for a harried stranger, often prompts the recipient to extend a hand to others, but it comes at a cost, psychologists have long argued. People who have done the good deed are primed to commit a rude one later on, as if drawing on moral credit from their previous act.Now, in a novel survey of everyday moral behavior, researchers have tested whether that theory holds up in real life. It does, though the effects appear small.The findings come from a survey of everyday morality in which researchers tracked people’s moral judgments and attitudes at regular intervals throughout a typical day, using text messages. Previous research on moral behavior had been confined mostly to the laboratory, with subjects making hypothetical, life-or-death decisions that they would never encounter in daily life.
http://www.nytimes.com/2014/09/12/science/a-window-into-everyday-morality-via-text-message.html