Why did more than 20 passersby leave a homeless man to bleed to death on a New York City sidewalk last week?
It's not necessarily because they didn't care, experts say. Their behavior may be a symptom of city living.
Hugo Alfredo Tale-Yax, 31, collapsed on a Queens, N.Y., sidewalk after he was stabbed several times by a mugger, but his motionless form didn't inspire a single passerby to help or to alert the police -- until he had been lying there bleeding to death for more than an hour.
The incident, captured on a surveillance camera, began around 5:30 a.m. on Sunday, April 18, when the homeless man sprang into action to thwart a man attempting to mug a woman on the street.
But though the homeless Good Samaritan risked -- and ultimately sacrified -- his life to help a stranger, his kindness was not returned by a single one of the more than 20 people who passed his wounded body on the sidewalk. In fact, the video showed, one man rolled over Tale-Yax but then walked away and another used his cell phone to snap a picture of the dying man.
By the time a 911 call directed firefighters to the scene, Tale-Yax was already dead. The woman he saved, as yet unidentified, had fled the scene before he even collapsed.
Like past cases in which bystanders failed to help those in need, this story begs the question, "Why did no one stop to help?"
Human behavior experts offer a few explanations for the public's failure to get involved..
Sometimes it's the "bystander effect," a phenomena that occurs when individuals fail to respond to an emergency because they assume others present will act, said social psychologists.
This term was coined following the 1964 murder of Kitty Genovese, a young woman who was stabbed to death in another neighborhood in Queens while several of her neighbors looked on.
While some reports liken the Tale-Yax tragedy to the Genovese case, there are some key differences, noted Paul Wolpe, director of Emory University's Center for Ethics.
In the Tale-Yax case, the passersby were individuals rather than part of a group, so their responsibility was not diffused in the same way, he said.
"Studies show that if a person comes across someone in need of help, being alone makes them more likely to help. If there were 10 people, there is less of a sense of personal responsibility," he said.
Art Caplan, director of the Center for Bioethics at the University of Pennsylvania, adds that another key ingredient for helping was missing: witnessing the trauma.
"When you don't witness the assault, you are less inclined to help because you're not sure what's going on when a person is lying there," he said.
The fact that the victim was homeless compounded the uncertainty about what had occured and whether help was needed, said Wolpe.
"When you see homeless people sleeping on the streets all the time, another body on the street becomes unremarkable," he said. Had Tale-Yax been wearing a three-piece suit, he would likely have gotten more attention because it is unusual for a well-dressed man to be lying on the sidewalk, Wolpe said.
"We categorize homeless people as the kind of person that we pass and don't help -- we do this every day in New York City. It becomes business as usual," he said.
The failure to help is tied less to acceptance of life on the streets and more to disdain for homeless people, said Caplan.
"People see the homeless as a blight, like spilled garbage. They wouldn't even think to pay attention to whether they were in trouble. Homeless people don't get looked at that way. It's dehumanization and it's terrible."
Wolpe said he hestitates to criticize those who passed byTale-Yax "because though we imagine that we would have stopped, studies show that in these situations, most people don't."
Though we view ourselves as altruistic, when it's time to act, other motivations often get in the way, Wolpe said. They can be as primal as fear of personal harm. Or as simple as being in a rush.
That was the challenge facing Princeton University divinity students who were put to the Good Samaritan test in 1973. The students were asked to give a spontaneous sermon on why people should always stop to help strangers, but were instructed to go to the church immediately to deliver the sermon and not to arrive late. En route, the students passed a man slumped in an alleyway, in a state of unknown distress. Unbeknownst to the students, the man was acting the part for the study.
Though these priests-in-training were about to preach about helping strangers, only 10 percent of them actually stopped to help the man when they were put in a "high hurry" situation.
"There you have it," said Wolpe. "That's the difference between someone's tendency to see themselves as good and how people actually behave when the time comes and their own lives and concerns get in the way."
ABC News conducted its own altruism study in March 2009, enlisting actors dressed as either a homeless man or a well-dressed woman to faint in the street.
While many passersby rushed to the aid of the well-dressed woman, most people ignored the homeless-looking man. The exception was one female passerby who had been homeless herself in the past, and who stopped to see if the man lying in the street needed help.
When interviewed, those who walked past the "homeless" man cited fear of personal harm and the dangerous nature of cities as reasons they failed to act.
"Especially in this area, you don't know," one bystander, Peter McKnight, told ABC News. "People come up with all kinds of scams, all kinds of situations to try and take advantage of being nice. And therefore, you have to be very careful."
This culture of fear helps explain why people might have ignored Tale-Yax, said John List, professor of economics at University of Chicago.
"People systematically think about the probability that the person really needs their help and weigh it against the probability that helping will put them in danger," he said. In a city, people are more likely to suspect that others mean them harm.
"Fear of the other" is instilled in us from childhood on and "makes it hard for people to respond to the needs of strangers," said Wolpe.
Because children are taught to be wary of strangers, they often grow up to be people who do not know when it is right or safe to intervene to help a stranger, Wolpe said.
"I'm not saying we shouldn't be teaching kids not to get in cars with strangers, but it's really important to balance that with an ethic of caring and intervention," he said.
Teaching kids only "safe" ways to contribute, such as donating money to charity, doesn't teach them how to act when a situation arises and their help is needed. "People don't know how to handle that" and their fear of taking risks conflicts with their desire to help.
Even if you are afraid to intervene physically, you can always call 911, List said. Pushing those three button requires little time and no risk, he said.