Primary age vs. secondary age in logarithmic units. Open symbols are target binaries with unreliable age measurements because either their primary (triangles right) or secondary (triangles up) or both components (diamonds) are spectroscopic binaries or exhibit a strong color-excess E(K_s−L′) > 0.5 (or H−K_s> 0.6, if K_s−L′could not be measured). Filled symbols with error bars are binaries with spatially separated components with low color excess. The dotted line is the reference for coeval ages.