Tools track American life
A one-of-a-kind project, 50 years in the making, reveals how we live, work, struggle and prosper.
Do blonde women have lower IQs than other women? Does eye color have any connection to alcoholism? Do college freshmen really gain the dreaded 15 pounds? Is there a link between obesity and what people earn?
Answers to those questions — and thousands more — are held in a one-of-a-kind data treasure trove that Ohio State researchers have managed for 50 years. The National Longitudinal Surveys (NLS) program has interviewed nearly 54,000 men, women and children since its launch in 1965.
Researchers across the United States and internationally analyze the data to get deeper insights into how Americans fare during different stages of life. They also explore how childhood influences play out later in the job market, in families and across communities.
“It’s like the census on steroids or some more powerful drug,” joked Elizabeth Cooksey, an Ohio State sociology professor and director of the Center for Human Resource Research, which helps run the
Unlike the census, which is a snapshot in time, the NLS interviews the same people year after year. This longitudinal study approach — which follows people and, in many cases, their children — helps researchers find connections and causes that are impossible to nail down in a snapshot survey or poll.
Cooksey uses the analogy of a train station to explain the difference. A typical survey would describe the trains in a particular station. A longitudinal study would do that as well, but also would detail where each train is coming from and heading to and provide information about stops along the way.
With the NLS, researchers track people on their journey through life. They’ve found that natural blondes have higher IQs than women with other hair colors. People with light-colored eyes experience higher rates of alcohol abuse than those with dark eyes. Thankfully, the freshman 15 turns out to be a myth. However, obese Americans do see lower wages and higher unemployment than other workers — an impact that’s even greater among obese women.
“I tell people that chances are you’ve seen our data in the national news,” said Kathryn Moneysmith, technical editor at the center. “We may be flying under the radar, but we are providing data that is making national headlines.”
The center has tallied more than 8,500 citations to NLS data in research papers, journal articles, dissertations, books and news stories.
“Ohio State’s success in conducting these national surveys has helped make the university a world leader in social science research,” Ohio State President Michael V. Drake said. “We are proud to lead a critical data resource that supports researchers from around the world in finding solutions that elevate society.”
Last summer, Ohio State received a $52 million contract renewal from the U.S. Bureau of Labor Statistics to continue its work on the survey through November 2019. Since it began, the program has brought more than $400 million in funding to the university.
Beyond its financial benefits, the program has bolstered Ohio State’s international reputation for groundbreaking research.
“The NLS is a complete feather in the cap of Ohio State,” said Claire Kamp Dush, an associate professor of human sciences and sociology and graduate studies chair in Human Development and Family Science. “NLS is synonymous with Ohio State.”
In grant proposals, she and other researchers can point to the program as evidence that Ohio State knows how to do deep research.
More than 100 Ohio State doctoral students have used NLS data in their dissertations. As alumni, many continue to mine the information in their research at universities across the United States. Among them:
- Daniel L. Carlson ’06 MS, ’10 PhD, assistant professor of sociology at Georgia State University, has published research about neighborhoods as well as racial disparities in risky sexual behavior among teens.
- Kevin Shafer ’02, ’05 MA, ’09 PhD, assistant professor of social work at Brigham Young University, has researched children’s views on second marriages and stepfathers.
- Lori Kowaleski-Jones ’96 PhD, associate professor in family and consumer studies at the University of Utah, has studied grandparents’ influence in families headed by single moms.
“The NLS is a complete feather in the cap of Ohio State.”
— Claire Kamp Dush, an associate professor of human sciences and sociology and graduate studies chair in Human Development and Family Science
“People come here from all over the country and around the world to learn how to use it,” Kamp Dush said. “The findings show up in high school and college textbooks in a variety of subjects. News releases and media coverage get the findings to the public and to lawmakers. You are hoping that policymakers are paying attention to this.”
Anyone can access NLS data for free at the U.S. Bureau of Labor Statistics website. In 2014 alone, 2,250 registered users downloaded survey data.
The NLS isn’t used directly as a recruiting tool, but several researchers say the program drew them to work at Ohio State.
“To have NLS here at Ohio State in our backyard is amazing,” said Cynthia Colen, an associate professor of sociology. “It’s one of the things that brought me to Ohio State in the first place.”
To celebrate the survey’s 50th birthday, the Journal of Marriage and Family will publish an entire issue of research papers based on NLS data. Cooksey has agreed to serve as editor of the publication, which is due out this summer.
Kamp Dush and graduate student Rachel Brown have submitted a paper for consideration about the correlation between the expectation of marriage and juvenile delinquency. They found that adolescents who have greater expectations of getting married are less likely to engage in criminal activity — even before the wedding vows.
Researchers at Ohio State and other universities can make a career of diving deep into NLS data to discover important patterns and connections.
One of the hallmarks of the NLS is its appeal to a remarkable range of disciplines — people who are on “different sides of the moon” academically, said Paula C. Baker, a senior research associate at the center. Those areas include criminal justice, economics, education, nursing, psychology, public health and social work.
Because the surveys have thousands of data points from thousands of participants who complete a lengthy questionnaire, researchers can look for differences and patterns based on gender, age, race and other factors.
What makes NLS data so special is that it follows people over time and includes different generations of the same families.
“So much in social science is the ability to establish a correlation between these two conditions or characteristics. But correlation is so different from causation,” Colen said.
So while many surveys can find connections among various traits and behaviors, a longitudinal study can pinpoint which factors actually cause or contribute directly to specific outcomes.
The NLS, Colen said, “shows the value of good data,” findings that can lead to solutions: “How do we make the health of our people better? How do we reduce disparities in health outcomes? If we can’t diagnose the problem, we can’t figure out ways to fix it.”
Often, the results are surprising.
Take Colen’s research on the benefits of breastfeeding, a study that sparked a national firestorm in 2014. The analysis showed that the long-term benefits of breastfeeding might have been overstated in earlier studies because wealthier, better-educated women tend to nurse their babies.
With NLS data, Colen was able to examine outcomes for siblings to see if those who were nursed and those who were fed from a bottle had different outcomes. On 10 of the 11 standards to measure child health and well-being, breastfeeding made no statistically significant difference among the siblings.
“I remember when I saw the results, I sank in my chair,” Colen said, realizing the controversy her conclusions would ignite. Indeed, the findings garnered national media attention and prompted angry emails from across the country. “It turned out to be a good conversation starter because we have to look at these broader social issues that affect outcomes with breastfeeding.”
In addition to tackling serious topics, researchers can have a bit of fun with NLS data.
“Not all research has to be rocket-level science or sequencing the genome,” said Jay Zagorsky, an economist and research scientist who works for the center. “There are lots of questions that ordinary people have about how we live and how they compare to others. The NLS can help answer serious questions about social issues and also can help us understand some fun issues about life in the United States.”
Consider the freshman 15 — those unwanted pounds that college students supposedly gain during their first year on campus. Using NLS data, Zagorsky and researcher Patricia Smith of the University of Michigan-Dearborn dispelled the myth. Freshmen typically gain 2.5 to 3.5 pounds, the researchers found, about a half-pound more than young people who don’t go to college.
And then there are the blondes. Zagorsky recently ran the NLS numbers and found a correlation between women who are natural blondes and women with higher IQs.
He’s also tackled money matters. After divorce, for instance, men tend to have higher incomes than their ex-wives. However, both suffer a significant loss in overall wealth — savings, investments, property and other assets.
In a recent paper, Zagorsky found that military veterans, regardless of how much time they served, have lower wealth than people who never served, a finding that may have implications related to troop readiness. “You don’t have a military that’s fully focused if they’re worried about paying the bills at home,” he pointed out.
Thousands of NLS participants have taken time every year, or every other year, to answer more than an hour’s worth of questions. Many of the topics are deeply personal, from details about household finances to their sex lives.
So why do they stay in the study?
“Most of them see their involvement as part of a greater good,” said Rosella Gardecki, an NLS principal investigator at the Ohio State center. Participants know that, collectively, their individual answers paint a broader picture of life’s transitions — from school to work, from single life to married, from worker to retiree.
Participation rates have remained high over the years — about 80 percent among eligible respondents. A small financial incentive, typically less than $100 per survey, helps reward people for their time.
The identities of survey respondents, as well as their answers, are closely protected to ensure participants’ privacy. The center’s technology team has developed special software and network protections to guard against hacking or other intrusions.
To mark the survey’s 50th year, program staff interviewed a longtime participant.
“I thought it was interesting, I guess, to be able to participate in something where I could give simple answers about myself, but have that paint a broader picture of what my generation was looking like,” said the woman, whose full interview is posted here.
Because she has taken part since 1979, the woman has seen the survey evolve. Topics added along the way include same-sex relationships, concussions and military service in combat zones vs. actual combat.
“One of my favorites, several years ago, was they asked how often my husband and I laugh together,” the woman said. “I decided that was a really good way to determine the health of a marriage. … It’s obvious that they’re putting a pretty good puzzle together of the balance of life.”
The study has expanded to include her children and more than 11,500 others born to women who joined the survey in 1979.
Initially, moms answer questions about their children. As they get a bit older and go to school, the children themselves take cognitive tests and answer questions about experiences at home and school. They remain in the survey as adults.
“One of my favorites, several years ago, was they asked how often my husband and I laugh together.”
— NLS participant since 1979
“So, now there’s generational information beyond my own to see how the decisions my husband and I have made over the years have now impacted my children,” she said.
The center regularly sends information to participants about how the study is being used and how it’s showing up in headlines across the country. “So, the reason for the loyalty, I guess, is because I think we are getting good information from it,” the woman explained.
Cooksey added: “The respondents really feel part of a group. They have a voice.
Those voices, joined together for so many years, have revealed insights that — 50 years after the survey program’s start — continue to make news, change perceptions and alter policies.
In coming years, you can expect to hear more research findings about children born to older mothers, data that will complement earlier research on the consequences of births to teen mothers.“We don’t know a lot about children born to older mothers,” Cooksey said, pointing to the fairly recent trend of women in their 40s having babies. “We’ll have to wait to see what happens to these kids, just as we did with the children born to teen mothers. But we will have the data.”
Those findings, undoubtedly, will make headlines in the years to come. So, too, will other NLS research revelations that help Americans learn more about themselves and each other.
Ohio State has helped run the National Longitudinal Surveys program since it began in 1965 as a five-year study of the workforce and significant life experiences. That program exceeded expectations, so the NLS program grew and morphed over the years to include nearly 54,000 men, women and children.
The NLS program was the first major project of Ohio State’s Center for Human Resource Research, founded in 1965 by Herbert S. Parnes and Samuel Clifton Kelley. For years, researchers referred to the NLS as “Parnes data.” On April 11, the program will mark the 50th anniversary of the first NLS interview.
From 1965 to 2003, Ohio State administered the program in partnership with the U.S. Census Bureau. Beginning in 1978, Ohio State teamed up with the National Opinion Research Center (NORC) at the University of Chicago to run the program. Along with the Bureau of Labor Statistics, NORC designs the survey launched in 1997, and Ohio State designs the survey that began in 1979 as well as the Child and Young Adult surveys. NORC conducts interviews for all surveys, while Ohio State standardizes and cleans the data, prepares documentation for users, assists researchers and administers other aspects of the program.