After Germanwings Flight 9525 crashed into the French Alps last month, the questions started out simple. Who or what caused the crash? Was it terrorists? Engine problems? A strange weather incident? Flight control issues?

When the answer was revealed to be a pilot — acting alone, with no known motive beyond his own self-destruction — the questions intensified: did the airline know he was depressed? Should it have known he was depressed? Could it have known he was depressed? Did the agency err in having lax guidelines for the number of pilots required to be in the cockpit? Was the German government complicit in the lack of knowledge of the pilot's mental state because of the country's strong health-care privacy laws?

This is a familiar pattern of questioning: when Adam Lanza shot and killed dozens at Sandy Hook Elementary School, a frenzied search for answers followed. What took the school so long to lock down? Why did Lanza's mother let him have guns? Why did the government allow the purchase of those types of guns? Were we as a society paying enough attention to those with autism spectrum disorders?

Punishing someone for a past event doesn't always make it easier to prevent bad events in the future

And again with Elliot Rodger, the "Santa Barbara killer" who left lengthy YouTube manifestos online and in print about killing women he felt had spurned him before he took to the Southern California streets with a handgun. How did people miss these public messages? How were the threats not flagged? How did his parents not know about his dangerous behavior? Did the sexual objectification of women in video games and media contribute to Rodger's sense of entitlement to female affection?

At least in the case of Andreas Lubitz, the Germanwings pilot, the answers to all of those questions might very well be "no": while Lubitz did tell the airline in 2009 that he was depressed and needed a break from training, almost nothing in his more recent medical history or treatment gave any indication that an incident like this could have happened. So it seems like the blame ends at Lubitz. Then why do we keep looking for answers and trying to hold others responsible?

Our impulse to blame is strong, but it's also complicated and imperfect. Cognitive psychology tells us that following a negative event our impulse to blame has both an emotional "why" component driven by anger and sadness, and a more rational "who or what is going to make sure this doesn't happen again" set in motion by anxiety and fear. These processes are closely related and often at cross-purposes. Punishing someone for a past event doesn't always make it more likely we can prevent bad events in the future. Conversely, making things safer in the future doesn't always give us the vindication of punishment. Having a better understanding of why we blame and what we're seeking when we do can perhaps get to a more satisfactory — and productive — end.

"People see something happen and they want to know why"

The first step in satisfying the questions we ask after a tragedy requires finding a person to blame. The answer in the Germanwings tragedy, though obscured in the immediate aftermath of the crash, is now clear: Lubitz.

That brings us to the next question, one of intentionality: did Lubitz do it on purpose? If he hadn't — if he had a heart attack, for instance, and fell forward onto the controls — we would hold him much less accountable. But here, Lubitz's actions were unequivocally purposeful. Which leaves us grappling to find an explanation, to try to understand Lubitz's reasons for committing such a horrible act.

"People see something happen and they want to know why," said Bertram Malle, professor of psychology at Brown University and author of A Theory of Blame. "That's true for even small events in the world — your pants have a rip or your car has a scratch in the paint, and you want to know why. And when someone acts intentionally, you want to know what the reasons are."

There are many "reasons" for a person to crash an airplane. Oft cited are: religious extremism, inciting general terror, political extremism, and personal gain. But Lubitz had no "reason" to crash flight 9525 and kill everyone on board — he was mentally ill, severely depressed, and he wanted to die.

"In this case, there are no understandable reasons for his actions," said Malle, "and that's dissatisfying because it fundamentally leaves us in flux, with no answer to our ‘why.'"

There are a few more exacerbating factors that make it so unsatisfactory to let the lack of answers — or the blame — end with Lubitz.

"There are no understandable reasons for [Lubitz's] actions, and that's dissatisfying"

"This situation is especially difficult because the person who is obviously responsible killed 150 people and himself," said Lawrence Solan, professor of law at Brooklyn Law School and author of Cognitive Foundations of the Impulse to Blame. "We now know he was mentally ill, but if you're that sick it's hard to ascribe moral responsibility."

The reality Solan describes is reflected in our legal system's concepts of culpability: we do not think blame or accountability should be placed on people with diminished mental capacity; we place little or no blame on children, those with developmental disabilities, or, in some circumstances, those with mental and emotional problems.

Moreover, as was the case with not only Lubitz but also Lanza and Rodger, the event culminated with their suicides. Not only does that mean we can't ask the perpetrators for answers — or punish them for their actions — it also means we can't satisfactorily answer the other side of the blame equation: how do we keep this from happening again?

"If you see someone who is perfectly fine in principle but then kills himself, in theory you suddenly look around, see a person you care about that seems fine and you have to think, ‘They could kill themselves, too,'" said Malle.

Combine this with the magnitude of an event like the Germanwings crash or Sandy Hook, and you have blame that can be extended much further than if Lubitz had just been in a plane by himself or with one other co-pilot.

The cascading chain of blame

This is what leads us to look down the chain of causality, to those with varying degrees of obligation to act as Lubitz began his sabotage. The closest actor — the co-pilot, who we now know died as he tried desperately to reenter the cockpit and stop Lubitz — was physically blocked from preventing the attack, and therefore unlikely to be blamed.

From there, we look to people and agencies who might have known about Lubitz's mental state but let him fly anyway: to his employer, Germanwings, which could have or should have known about his mental health issues; to the employer's parent company, Lufthansa, for instituting policies that might have contributed to Germanwings' failure to ask questions; to Lubitz's doctors, for not alerting anyone of his potentially worsening state; and to his family and friends, for not noticing the signs of suicide or deep depression.

Finally, when and if it is hard to ascribe blame to the above, we look even wider: to the flight agency policies that approved his licensing and made rules that allowed just one pilot to be in the cockpit, or to the German state, which created strict privacy laws that made it difficult to suss out or disclose this kind of mental illness.

For some of these questions, the answer can come from the legal system. Germanwings, via its parent company Lufthansa, is subject to strict liability laws — which means Lufthansa will have to prove that it could have done almost nothing to prevent the crash. That's a very difficult task, and a reason almost every modern airline crash case settles out of court with the victims' families and estates. But if the law recognizes that the airlines are virtually de facto to blame, why are we still looking for answers?

"If you have an impulse to blame, the criteria you look at will also trigger decisions about legal responsibility — but they're not really always the same thing," says Solan. "Assigning them moral responsibility is more satisfying, and it also helps answer the question of how to prevent this from happening again."

This is the second part of blame. If the search for the answer to "why" is a primary emotional response to anger and sadness, then this is the more "rational" part that tries to gain a semblance of control, to soothe the anxiety and panic that emerge in the wake of such a massive tragedy.

The problem of trying to "fix" a tragedy

In the Germanwings case, lots of possible solutions have been proposed to prevent similar future situations, and some have already been put in place. In Europe, at least four airlines have announced they will adopt new cockpit rules to require two pilots in the cockpit at all times while in flight. Discussion about redesigning cockpit doors has begun. And calls to change legislation around mental health privacy has been proposed in Germany.

The impulse to "fix" the problem so it doesn't happen again is a natural one. But it is unclear whether it is a wise one.

"The result is you wind up with laws that are hyper-reactive to situations," explains Solan. "The traditional notion of Madisonian republicanism is precisely because if you do things too quickly, in reaction to immediate situations, you'll respond to blame impulse and not more contemplative pragmatic ideas."

While we can't quash our impulse to blame, we can do something about how we react to it — by slowing down

The potential folly of hastily passed laws in response to tragedy is ironic in the Germanwings case. As even Lubitz discovered in his searches prior to crashing the plane, the reinforced cockpit doors that his co-pilot was unable to open were mandatorily reinforced in all aircraft only a month after the 9/11 attacks on the United States. Today the doors are too strong; 10 years ago, they weren't strong enough.

Pilots and aircraft experts have pointed out that even if Lubitz's co-pilot had been present in the cockpit or able to open the doors, there is little he could have done. "It turns out that things can go bad very quickly in a jet. Pushing one button will cut off the fuel to an engine . . . [s]tomping on the rudder can break off the tail of an Airbus . . . [p] ushing forward on the stick or yoke can put the airplane into a 30-degree nose-down attitude within a few seconds. . . Automated systems can be disabled by pulling circuit breakers," writes Philip Greenspun, a pilot and engineer who publishes a blog on flying and aviation. History teaches this, too: in 1999, EgyptAir Flight 990 crashed into the Atlantic Ocean when one co-pilot seized the controls, with the other pilot present, and flew the plane into the sea, killing all on board. But when you have an enormously tragic event where hundreds are killed, impulse to blame can trump this kind of expert and historical knowledge.

How we should actually respond to disasters

So what is a better way to go forward in the wake of such tragedies?

The answer, told to us by both history and cognitive psychology, would seem to be: very slowly and deliberately. A contrast to the story of Lubitz or Lanza is that of Dzhokhar Tsarnaev, the Boston Marathon bomber. In the months following the attack, surveys of Americans found that 70 percent favored the death penalty in his case — but two years later and in the wake of a guilty verdict, only 47 percent thought the death penalty should apply. The time and deliberation associated with a trial seems to have eased some of the initial impulse to blame or punish.

And while we can't quash our impulse to blame — and wouldn't want to — we can do something about how we react to it, simply by slowing down.

"[Mechanisms like] stretched-out investigations help people to calm down and think relatively rationally," says Malle. "It helps them to acknowledge they can never be completely safe, and ultimately to learn to live with that."