How much longer than the rest of us do royals live for? And do kings and queens enjoy a "healthy stress"?

For centuries, Europe’s royals enjoyed standards of living that most of their subjects could only dream of, reports Joan Costa-Font. This “royal advantage” is now quite small, but monarchs continue to outlive their (non-ruling) siblings and consorts – suggesting a health boost from the “positive stress” associated with a strong sense of purpose and agency. If that is right, what does it mean for wider health policy debates?