High school and college are the glory days, and it's all downhill from there, right? Until now, research has supported that popular idea, suggesting that life satisfaction reaches its low point in middle age. New findings, however, suggest that we continually get happier well into our 30s and perhaps beyond.

Past studies that attempted to look at lifelong happiness used a cross-sectional method. At a given point in time, a research team would survey demographically matched groups of people who were different ages. These studies consistently found that the youngest and oldest adults were most satisfied with their life. Happiness seemed to follow a U-shaped curve: higher in the teens and early 20s, then steadily falling to a low point in middle age before increasing again.

The problem is that people in different generations might be on different trajectories. “Cross-sectional is a nice first pass, but it can't be a final word,” says Daniel Mroczek, a psychologist at Northwestern University who was not involved in the new study. To paint a more accurate picture, researchers at the University of Alberta analyzed data from a longitudinal study that followed 968 high school students until they were 43 years old and another group of 574 university students until they were 37. The groups filled out surveys about happiness at seven time points from 1985 to 2010, revealing that their levels of life satisfaction increased steadily with only a slight downturn at age 43 for the high school cohort. Even with the downturn, happiness at the final time point was significantly higher than it had been initially. The results held when the researchers controlled for factors such as socioeconomic status, marital status and physical health.

Although the longitudinal data are strong, there may be factors affecting the Canadian population studied—such as a stable economy and universal health care—that would not hold true for other populations. Even so, it is important to recognize that feeling unsatisfied in midlife may not be the norm. “One danger of thinking that midlife is a low point is that if someone does have a crisis (for example, depression), the person might not seek help,” says Nancy Galambos, a developmental psychologist at Alberta and lead author of the study.