People indeed lost their homes and incomes, and markets closed. But the World Food Program had enough supplies in its Port-au-Prince warehouses — which survived the quake — to feed 300,000 people one full meal for three weeks. There was no acute food or malnutrition crisis after the quake; that much we know. But it seems very likely that the city could have avoided one even without the frenzied aid push.

Our focus on the organized rescue efforts was similarly misplaced. The constant media coverage and well-financed, specialized rescue teams created the impression in many viewers’ minds that large numbers of people were being saved by outside responders. In fact, according to a report by the French Defense Ministry’s Haiti mission, no more than 211 people were saved by all of the international search-and-rescue efforts combined, in a disaster in which hundreds of thousands were trapped.

This isn’t the responders’ fault; they worked as hard and as fast as they could. But disaster experts routinely note that a vast majority of rescues after an earthquake take place within the first 24 hours, and are almost always done by people from the area using their hands or simple tools. By contrast, the first American search-and-rescue team didn’t arrive in Haiti until nearly a full day after the disaster.

As for the notion of post-disaster disease outbreaks, epidemiologists have gone looking for evidence of epidemics resulting from calamities like earthquakes, and they have generally concluded that they don’t happen. (“The news industry is prone to emphasizing more dramatic and simplistic messages, and unjustified warnings will likely continue to be spread on the basis of an approximate assessment of risks,” the authors of a 2006 study wrote in the journal Emerging Infectious Diseases, published by the Centers for Disease Control and Prevention.) If you look closely, news reports tend to cite unspecified “fears” or “threats” of disease, often sourced to nongovernmental organizations like the Red Cross. But those sources are rarely asked to produce any actual evidence.

There is violence after disasters, just as there is violence every day wherever humans live. But taking a hard look back puts the lie to the idea that societies somehow become less cohesive after a natural shock, at a moment when most people are busy trying to put their lives back in order. After Hurricane Sandy, in 2012, crime fell in nearly every category in New York City. (The murder rate in Nepal’s capital, Katmandu, when it was last measured nearly a decade ago, was higher than New York’s but comparable to Chicago’s in recent years.)

There is no way to know for sure if that was true in Port-au-Prince; crime statistics were unreliable before the quake and nonexistent after. The escape of prisoners from the city’s national penitentiary did lead to a series of murders over turf in the slum Cité Soleil, and there were reports of increased sexual violence in the months after the disaster. But there was no widespread civil unrest of the magnitude that would justify keeping 20,000 United States troops on call. Having been there at the time, I recognized the sentiment expressed by Donatella Lorch, a Katmandu-based writer, in The Times this week: “I am buoyed by the generous spirit of [Nepal’s] people. My son and I know that life here will get worse in the days and weeks ahead as fuel and water run low. But we also know we are in this together.”

These myths come with consequences. Rash decisions made in the heady days after a disaster, when everyone is committed to the response and the money is flush, are fiendishly difficult to undo. In Haiti, fears of insecurity led to a militarized response that concentrated too much assistance in certain parts of the capital, poured money into defense and security measures when it would have been better spent elsewhere and often treated survivors as threats rather than people to be helped.