Turns out, the best-looking people raised more money.
"When you go from the average physical attraction from a five to a seven that will cause twice as many households to give," List said.
Economists point out that the amount we give almost always has some sort of strings attached.
Colleges and universities promise donors they'll etch names onto buildings. And in doing so, the colleges get their donations. Charities throw big parties, where high society donors can see and be seen. And the charities win, too. And the local church figured that out long ago. There's a reason why that basket passed around is open. Everyone can see what everyone else is giving.
So, are we more altruistic when we know someone is watching us?
"Yes. Scrutiny," Dubner said. "If you want to make people be generous, scrutinize them."
But there have to be some people who are truly altruistic. How do you explain the New York subway hero, who jumped onto the tracks to save a young man who'd fallen into the path of an oncoming train? Dozens of others stood by and watched.
"There are those saintly few who seem to be altruistic all the times under every circumstance at whatever the cost to themselves," Dubner said. "Think of whoever your mind conjures -- Mother Teresa, some people might say. The reason your mind can conjure those people are because there are so few of them. If there were a whole lot, they wouldn't come to mind so easily."
So, if there really are a saintly few who are purely altruistic, where do the rest of us fall?
Levitt and Dubner say most of us fall somewhere in between. It just depends on what's in it for us.
"We found out that people aren't as bad as you think they are, but they're probably not as good as you think they are, either. People are people," Dubner said.
Forty-five years later and back to that night Kitty Genovese was murdered: Were all of those people really as apathetic, as uncaring as they seemed? Turns out, what we've thought for 45 years about those apathetic neighbors was wrong.
"Most people imagine the crime as 38 people sitting by their windows or standing by their windows watching for half an hour while a woman is brutally murdered," De May pointed out. "That didn't happen."
De May says only a few neighbors actually saw anything. Most woke up confused. It was a cold night, so the windows were closed. Some only made it to their windows after Genovese got up. Others thought they were hearing noise from a rowdy bar.
But, had the story been reported accurately all those years ago, would we still be talking about it today?
"It might have been a four-day story. It might have been a four-week story. It would not have been a 45-year story," De May said.
And just how was Genovese's killer finally arrested? It was just a few days after the murder. Moseley was seen stealing a television set out of someone's home.
One neighbor ran to call the police while another removed the distributor cap on Moseley's car, disabling it and keeping him from getting away.
Minutes later, the killer was under arrest. And in the end, all because of neighbors who saw something...and helped.