What’s the key to a longer life?

A study that started in 1940 says it’s simple: happiness.

Instead of social factors like class and wealth affecting the long-term well being of the men they charted over the decades, it was marriage, puppies, and friendship that made their quantity of life improve.

Meeting a spouse later in life seemed to still have the same positive effect on lasting life, as it brought the men happiness in their later years.

Of the 31 participants that were single throughout the study, only four are alive today.