"When I was a boy and I would see scary things in the news, my mother would say to me, 'Look for the helpers. You will always find people who are helping.' To this day, especially in times of disaster, I remember my mother's words and I am always comforted by realizing that there are still so many helpers -- so many caring people in this world." - Fred Rogers

The exact details of what happened today on Boylston Street are still being sorted out, but multiple reports are confirming that two bombs were detonated close to the finish line of today's Boston Marathon, killing at least two people and wounding dozens of others.

As a social psychologist, there are so many reasons to expect that this should end up revealing an absolute low point for humanity. First of all, the bombing itself is just horrendous. I can't say any more about it, because there is nothing else to say. There is no perspective, opinion, logic, or reason that I could ever find to explain or even hope to understand any of it.

But based on what we know about altruism and helping behavior, there's another reason why a social psychologist might have expected that today would be even more dismal. After all, everything that our research says about altruism -- using phrases like "bystander effect" or "diffusion of responsibility" and throwing around names like "Kitty Genovese" -- points to the idea that in the wake of such a terrible tragedy, we should have been faced with a general public that shied away from cooperating, lending a hand, and providing crucial support and assistance to those in need. Yet after the explosion, spectators lent runners blankets, sweaters, and phones. People helped each other up, provided crucial assistance and care, and put their own needs on hold to attend to those of perfect strangers. Across the city of Boston, the past few hours has revealed an outpouring of support, cooperation, and altruism.

So why might we not have expected this outpouring of support today?

1. The Marathon was in Boston.

A cross-cultural analysis of helping behavior in rural and urban settings all around the world reveals that strangers are significantly less likely to help each other when they are in urban areas (like New York or Boston) as opposed to rural areas. An injured pedestrian or lost child, for example, would be far more likely to receive crucial help from an onlooker in a town of 1,000 people than in a town of 5,000 people, and more likely to receive help in the town of 5,000 than in the town of 10,000.

This is not because "city dwellers" are fundamentally jerks, nor is it because the rural folk are inherently more kind. We know this because it's the size of the town where the person lives now that matters when it comes to helping behavior, not the size of the town in which someone grew up. Rather, there are a couple of potential reasons why strangers tend to help each other so much more in small towns than in cities. First of all, Stanley Milgram argued that in large cities, people often fall victim to stimulus overload; if your senses are constantly being bombarded with lights, smells, sounds, and crowds, you quickly get used to narrowing your focus and shutting out most of that sensory input swarm when you go about your everyday life. If you're in this mode, it's easy to accidentally overlook someone who needs your help, simply because less of the environment will grab your attention at any given time. Secondly, there are effects of diversity. People are more likely to help others that are similar to them, like in age, race, or gender. Urban areas have more diverse populations than rural ones; this increases the odds that any given person who needs help will be somehow different from the potential helper. A somewhat dismaying finding, but potentially important nonetheless.

There were over 20,000 runners at the Boston Marathon this year, not to mention family members, friends, and Boston residents who came out to join the race day fun. Not only is Boston a major city, but the event itself contains its own unique brand of "stimulus overload." And diversity? People came to run Boston from all over the world! Any of the reasons why you would expect to see less helping behavior in large cities were certainly also present today at the Boston Marathon. And lest we forget another major factor...

2. More onlookers, less help.

Research on the bystander effect and diffusion of responsibility suggests that the more onlookers there are in a tragic or troubling situation, the less likely it is that any one of those onlookers will provide crucial assistance. This is why one of the best pieces of safety advice that any self-defense class can ever teach you is that if you find yourself in trouble, you should not just vaguely scream for "Help" -- you should single out specific people to target with your pleas. If you do not, people in large crowds will often assume that there are enough people around that "someone else will probably help," thereby diffusing the responsibility for helping and making it less likely that any help will actually be provided. In short -- more bystanders, less personal sense of responsibility, less help.

With this in mind, the fact that there was a humongous crowd at the Boston Marathon certainly should have made it very unlikely that anyone would step up and help the injured/panicking runners & spectators. The tens of thousands of people around should have made it much more likely that everyone would freeze, assuming that "someone else" would jump in and take responsibility for helping out.

3. It's difficult to help when the situation is ambiguous.

Many times, in an emergency, it's not exactly clear what's going on. What happened? What help is needed? Is this even an emergency at all?

Imagine being near the finish line of the Boston Marathon today when the bombs exploded. You hear two loud noises that sounded somewhat like thunder, according to eyewitness reports. You see smoke. Many people were not sure exactly what was going on -- was this planned? Is this an attack? Is this a mistake? What is even happening?

People are significantly more likely to provide help in a dangerous situation if they are clearly aware of what is going on. For example, in one study, participants who watched someone faint and slowly regain consciousness were much more likely to help out than those who simply walked in on someone who had already fainted. If you don't know what's going on, there's a lot more confusion -- a reaction that tends to lead people to freeze rather than actively help.

These were some of the big reasons why we might not have expected to see people helping today. This is social psychological research, replicated and confirmed dozens of times. This is what I teach my students in class each semester when we learn about "altruism." Everything in the Social Psychology textbook suggests that people should not have stepped up to help their community members, fellow runners/spectators, and complete strangers today. There was a large crowd, in a large city, thrown into a frightening, ambiguous situation. Research tells us that this is exactly the kind of situation that should lead people to freeze up, diffuse responsibility, and assume that "others" will help if it is needed.

But here's what I want to point out. Here's what I wrote this entire post to point out. That's not what happened.

When faced with unimaginable tragedy, in a terrifying situation where people did not know how to respond or behave, when no one could know if there would be any more bombs being detonated or any more people being harmed, in a set of circumstances that, by all logic and reason, should have discouraged most people from lending a hand, people still jumped into the crowd and helped. In droves. They stepped up, pitched in, helped strangers. They put themselves in potential danger to make sure that strangers were okay.

It's so easy to get dismayed about humanity on days like today. To wonder how people can do such horrible things. But this is why I like Mr. Rogers' words of wisdom. This is why I have decided, today, to look at the helpers. Because the helpers show us that even when faced with unimaginable tragedy, terror, and tumult, there is a monumentally strong force within each of us that truly wants to help our fellow man. We all have that seed of good. It can defy logic, reason, and empirical scientific data. And even when everything around us -- those "powerful situations" that us social psychologists love to say determine everything about what we do and who we are -- combines in perfect synchrony to create the exact blend of factors that should push anyone away from helping, we can't underestimate the power of that drive within us all that doesn't care about what the textbook says and pushes us towards doing good anyway.

What a beautiful thing.

Steblay, N. (1987). Helping behavior in rural and urban environments: A meta-analysis. Psychological Bulletin, 102 (3), 346-356 DOI: 10.1037//0033-2909.102.3.346

Milgram, S. (1970). The Experience of Living in Cities Science, 167 (3924), 1461-1468 DOI: 10.1126/science.167.3924.1461

Latane, B., & Nida, S. (1981). Ten years of research on group size and helping. Psychological Bulletin, 89 (2), 308-324 DOI: 10.1037//0033-2909.89.2.308

Darley, J., & Latane, B. (1968). Bystander Intervention in Emergencies: Diffusion of Responsibility. Journal of Personality and Social Psychology, 8 (4, Pt.1), 377-383 DOI: 10.1037/h0025589

Piliavin, J., Piliavin, I., & Broll, L. (1976). Time of Arrival at an Emergency and Likelihood of Helping Personality and Social Psychology Bulletin, 2 (3), 273-276 DOI: 10.1177/014616727600200314

Image from the aftermath of the Boston Marathon by Aaron Tang via Flickr; available under the Creative Commons Attribution 2.0 Generic License.

Image of the 2013 Boston Marathon bombings map by Anna Frodesiak via Wikipedia, created using OpenStreetMap; available under the Creative Commons Attribution-Share Alike 2.0 Generic License.

Image of Mr. Rogers with his quote on helping via Liberty for Kids.