The current state of affairs is pretty curious. We’re living longer than we’ve ever lived before, but are we any healthier? Alzheimer’s disease, for instance, wasn’t a problem in the early 20th century. Sure, we hadn’t discovered it yet, but that was because we didn’t live long enough to contract it. And where infectious disease used to grip young people, a new report shows violence and injury have taken its place.

The Centers for Disease Control and Prevention has collected data on cause of death since 1900, when diseases accounted for over half of all fatalities. Among today’s population, however, the culprits have switched to heart disease and cancer, which together account for 65 percent of all deaths. But this data doesn’t say anything about specific age groups. Under 30, people are their own hazards, to themselves and to each other. The findings could shed an important light on where social progress has yet to break through.

"Injuries and violence are not accidents and are not inevitable,” said lead author Dr. Tamara M. Haegerich in a statement. “They can be prevented.” Haegerich and her colleagues found between the ages of 1 and 30, in the year 2010, 79 percent of deaths were the result of various injuries; 20 percent came from cancer or other chronic diseases; and one percent stemmed from infectious disease. Of the portion caused by injuries, 60 percent were unintentional: an unlocked car seat, texting while driving. The remaining 40 percent split in half between suicide and homicide.

These data imply one of two things. Either medical science has progressed so far that violence- and injury-related deaths have begun to outpace physical and mental ailments, or we as a country are just becoming more aggressive and less careful. In reality, we probably fall somewhere in the middle of both factors. Leading theories such as the Hygiene Hypothesis, which suggests many of the nation’s emerging immune disorders stem from us being too clean, sit beside climbing rates of distracted driving deaths. Between 2010 and 2011, texting while driving rates shot up 50 percent. In the same year, nearly one in five crashes were the result of someone who was distracted.

"The scientific evidence to support prevention of injury and violence is strong,” Haegerich said. “We know the factors that place people at risk and it is possible to intervene with cost effective interventions.” Not all innovations need to be high-tech or costly to work; they just need people to follow through with them. Haegerich offers the example of seat belts. They are the single most effective device for preventing death or injury on the road. Of all the people killed in car crashes in 2007, 42 percent weren’t wearing their seat belts. But young drivers still remain the guiltiest group when it comes to wearing them.

People like Haegerich want you to stop thinking about car accidents as accidents. They are avoidable. At some point, someone made a careless decision, or indecision, before getting behind the wheel. Maybe she was drunk at the time. Maybe he forgot to buckle his seat belt. While these forms of injury are more gruesome and catastrophic, they come with a silver lining, which no infectious disease can. They’re a choice.

The supreme hurdle, as Haegerich sees it, is getting everyone on-board with this line of thought. It requires getting people on the top to devise creative strategies for empowering young people not to make unwise choices, and for people under 30 to accept their agency, and potential, for causing harm. Responsibility goes both ways.

“Although figures in public health maintain a common understanding of the definition, causes, and solutions to injuries and violence,” Haegerich said, “this recognition might not be widely accepted by other audiences, including policy makers, clinical health professionals, and the public.” Here’s to hoping we don’t have to keep learning the hard way.