On a cold night in March 1964, piercing screams woke a neighborhood in Queens, N.Y., and stunned the nation. Forty-five years later, the authors of "SuperFreakonomics," Steven Levitt and Stephen Dubner, reconsidered those cries for help and asked themselves, "Do we only care about ourselves?"
Twenty-eight-year-old Kitty Genovese was walking toward her apartment unaware that a stranger, Winston Moseley, was following her. He then took a knife out of his pocket and ran toward her.
"He stabbed her in the back two to four times with a hunting knife," Queens historian Joe De May said. "Kitty Genovese screamed bloody murder."
Lights went on in the apartment building across the street. Someone yelled out the window to leave her alone. Startled, the attacker ran back to his car and waited. Genovese summoned the strength to pick herself up and walked around to the back of the building, but she couldn't make it to her own apartment. Moseley found her, collapsed inside the vestibule to another apartment. He stabbed her again and left her to die.
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The crime would soon become infamous -- not simply because of the horrifying things done to Genovese -- but because of what her neighbors didn't do.
"For more than half an hour, 38 respectable, law-abiding citizens in Queens watched a killer stalk and stab a woman in three separate attacks," the New York Times reported. "Not one person telephoned the police during the assault."
The idea that no one would call for help -- no one from that apartment building would call police -- shocked an entire nation. It was the mid-60s, crime was on the rise, President Kennedy had been assassinated and people were asking: Do we not care about anyone but ourselves?
"The Kitty Genovese crime, the murder, became a symbol of all that was going wrong with the world," Dubner said. "Of how incredibly, cruelly selfish human beings can be."
The crime got social scientists wondering if we would ignore our own neighbors in need, how about those closest to us?
What the "SuperFreakonomics" duo found at retirement homes surprised them.
"If you're a parent in a nursing home, the best predictor that your child will show up is if you, the parent, are quite rich," Levitt said. "Children of rich parents are much more likely to show up in nursing homes than are children of poor parents."
But even that wasn't a guarantee.
"If you didn't have to compete against your brothers and sisters to go and get the bequest, you didn't show up at the nursing home," said Levitt.
It may sound depressing to think that's what drives us, but as Dubner said, "It would be depressing if we were all just cruel and selfish all the time, but we know we're not."
Americans donate $300 billion to charity every year, according to Giving USA 2009. Clearly, we are incredibly giving. So what gives? Is this pure altruism or does something else motivate us to give?
Economist John List of the University of Chicago has spent years developing creative experiments that shed light on what motivates people to be altruistic. In one experiment, he looked into what effect the appearance of a solicitor has on donations for charity.
List starts by taking pictures of his solicitors and has them graded on a scale from one to 10 by independent evaluators before sending them door to door to solicit money for charity.