Sérsic index at rest-frame 1.5 μm (left panel) and rest-frame 0.5 μm (right panel) as a function of redshift. Dots in the background represent n_λ of the individual star-forming (blue) and quiescent (red) galaxies. Filled circles show the median n_λ in redshift bins of width 0.25 and in four stellar mass bins from high-M_⋆ (dark) to high-M_⋆ (light). Error bars identify the statistical uncertainties computed as $\sigma /\sqrt{N}$ with N the number of galaxies within the bin and σ the standard deviation of the distribution. Solid lines shows results of the fits to n_λ ∝ (1 + z)^β_λ. In the top right corner, we report the number of galaxies in each stellar-mass bin using the same color coding, and we show the median uncertainty on the Sérsic index as a black error bar. The Sérsic index of massive galaxies evolves with redshift while that of lower mass galaxies does not.