People with higher levels of education generally live longer, healthier lives. Compared to Americans without a high school diploma, high school graduates are expected to live an additional 6 to 7 years and college graduates are expected to live an additional 12 to 13 years. Health-related behaviors are also closely linked to educational attainment — about 25% of Americans without high school diplomas smoke, for example, compared to only 9% of those with bachelor’s degrees.

Although there is a clear relationship between education and health, it is not clear that higher levels of educational attainment actually cause people to lead healthier lives — there are several alternative explanations. One is that the relationship between health and education is confounded by other factors. For example, a person who grows up in poverty may be more likely to die early regardless of how long she attends school. However, a person who grows up in poverty is also more likely to drop out of high school, potentially making it falsely appear as though shorter education causes poorer health. A second explanation is “reverse causation” — young people who suffer poor health in the first place will be more likely to miss school, drop out or not continue on to college. In that case, rather than limited education causing harm to health, poor health would limit a person’s opportunity for education.

A number of studies have tried to determine if there is a true causal link between education and health. A 2012 study looked at changes to Sweden’s school policies that occurred 50 years earlier. These changes increased the length of compulsory education by one year in some parts of the country. The study found that after age 40, those who lived in jurisdictions with longer compulsory schooling experienced a 4% reduction in the risk of death. Other studies, however, have not concluded that health improves with education. The authors of a 2010 literature review found that there was some evidence of a causal link between education and health, but write: “A note of caution is warranted, because not every association that has been reported between schooling and health outcomes is likely to be causal.”

A 2014 study published in Pediatrics, “Successful Schools and Risky Behaviors Among Low-Income Adolescents,” looks for a cause-and-effect relationship between education and health by seeing if low-income students at high-performing high schools in Los Angeles were less likely to engage in risky behaviors compared to their peers at other schools. The researchers, based at the University of California, Los Angeles; the RAND Corporation; ACT, Inc.; and Columbia University, took advantage of the random admissions lottery process for Los Angeles charter schools to conduct a natural experiment. The investigators compared two groups of students: The first consisted of students enrolled at one of three highly ranked high schools, while the comparison group consisted of students who applied to the lottery at one of those schools but were not selected.

The study’s findings include:

• Attending high-performing schools reduced students’ class cutting. For those who attended the high-performing high schools, 83% never cut class compared to 60% at other schools. Also, 1.4% of students cut class at least seven times compared to 6.5% of those at other schools. Students at the high-performing schools were also less likely to drop out or transfer schools.
• Standardized test scores were slightly better at the high-performing schools. While there were no differences for math tests, students at the high-performing schools were more likely to receive a score of “proficient” on the California Standards Test for English (45% proficient at high-performing schools vs. 40% proficient at other schools).
• Comparing the two groups of students, there was no difference in the likelihood of smoking cigarettes, drinking alcohol or smoking marijuana during the previous 30 days.
• Students who went to high-performing schools had 27% lower odds of engaging in “very risky” behaviors, including binge-drinking, use of drugs other than marijuana, unsafe sex practices, weapon carrying and gang membership. The evidence was not very strong, however, rising just above the threshold for statistical significance.

The study’s authors believe that two factors may have resulted in their underestimating the reduction in risky behaviors linked to attending high-performing schools. First, they speculate that their study included too few students to demonstrate statistically significant differences in behavior. Second, they note that it was more difficult to recruit students into the lower-performing control group; students who did agree to participate would likely have fewer behavioral problems than their counterparts.

Explaining the possible link between high-performing schools and less risky behaviors, the researchers write, “Factors that improve educational achievement may also reduce risky behaviors. For example, attending a high-performing school may lower exposure to ‘risky’ peers. Successful school environments may also improve persistence, resiliency, and other non-cognitive skills, which may lead to better outcomes.” They also note that spending more time on homework leaves less opportunity for participating in risky behaviors and that “better academic achievement may lead to a better future outlook and less risk taking.”

Related research: A 2014 study in the American Journal of Public Health, “Trends in Bullying, Physical Fighting and Weapon Carrying Among 6th- Through 10th-Grade Students From 1998 to 2010,” looks at changes in bullying at U.S. schools. A 2013 study for the National Bureau of Economic Research, “The Medium-Term Impacts of High-Achieving Charter Schools on Non-Test Score Outcomes,” looks at attendees of the Promise Academy in the Harlem Children’s Zone, one of the nation’s most high-profile efforts to reform outcomes in urban schools.

Keywords: children, youth, drugs, violence