For many of us, it’s almost impossible to avoid at least some self-evaluation during the holidays, as we transition from one calendar year to the next. So here’s some input and, perhaps, something new to think about at the start of the year.

Let’s look at the good news first: Over the past 50 years, life expectancy in the U.S. has increased significantly, by almost 9 years, from 69.8 in 1960 to 78.8 in 2015. (The measures here are based on “life expectancy at birth,” which is the average number of years a newborn infant would live if prevailing patterns of mortality at birth were to stay the same throughout his or her life.) The graph shows that this improvement for the U.S. (thick black line) has been relatively steady over the years. To be sure, adding 9 years to a life is a big deal. A longer lifespan allows us to enjoy more years of retirement and interact with family (including children, grandchildren, and great-grandchildren) but it’s also associated with better overall health over the lifetime.

But the graph also shows two patterns that also deserve reflection. First, the gains in life expectancy have been slowing down since the early 1980s, most notably in the past five years. Second, the U.S. was right in the middle of the pack in 1960 but is now lagging far behind all other developed countries. Indeed, in 1960, the U.S. was below the U.K. and Canada, essentially on par with France and Germany, but significantly above Japan and Italy. Fast forward to 2015 and you can see the U.S. is below all these countries by a significant margin: The Japanese and Italians are expected to outlive Americans by an average of five years, and the French are expected to outlive Americans by four years.

This comparison is among developed countries with comparable economic and geographic conditions (all are developed and all are in the Northern Hemisphere), but all these countries also have a presence in the genetic makeup of the U.S. population. So, what are the culprits that have caused the U.S. to lag behind? Food? Stress? Lack of exercise? Ingesting toxins and other risky behavior? Even if we knew the precise reasons, why would conditions be so different today?

How this graph was created: Search for “Life-Expectancy” and “United States.” From the Edit Graph” menu, select “Add Line” to add each of the other six countries, each time simply typing “Life-Expectancy” and the country name. Finally, to highlight the U.S. series, choose “Format” and select 5 for the width of the line and black for its color.

Suggested by Alexander Monge-Naranjo.