The National Institute on Aging has given Iowa State University a $1.9 million grant to continue a study of relationships spanning four decades and three generations.

Begun in 1989, the study has involved more than 550 individuals and their families, and it looks at both the emotional and genetic evolution of Iowa couples and families.

“What’s really neat about this study is we can go back and see if they’re married to the same person, and examine how the relationship has evolved over time,” said Tricia Neppl, an assistant professor in human development and family studies and co-director of the study, called the Family Transitions Project. “We studied them when their average age was 40, and here we are years later, looking at how their relationships have changed.”

With the new grant, co-principal investigators Neppl and Fred Lorenz, professor of  psychology and statistics, will examine the first generation of couples. These were the original participants of the study in 1989, people with an average age of 65.

The five-year grant will pay for two rounds of data collection for this portion of the study, called “Couple Relationship and Health During the Transition to Later Adulthood.”