It’s an impressive study, the longest scientific study of adult development, conducted across decades (it started in 1938). Referred to as the Grant Study or the Harvard Study of Adult Development, this famous research program has gotten several rounds of press.

But the press coverage seems to miss something incredibly vital and far-reaching in this study. Even the books have failed to make it clear. In a way, we could suggest the lead researchers of the study missed this finding—didn’t notice it, didn’t fully grok it, or didn’t understand how crucial it is.

This unstated finding is the most important finding about happiness and a meaningful and fulfilling life that we have.