  Motivated by recent experimental findings, we investigate the evolution of
the superconducting gap anisotropy in 122 iron pnictides as a function of hole
doping. Employing both a functional and a weak coupling renormalization group
approach (FRG and WRG), we analyse the Fermi surface instabilities of an
effective 122 model band structure at different hole dopings x, and derive the
gap anisotropy from the leading superconducting instability. In the transition
regime from collinear magnetism to s_{\pm}-wave, where strong correlations are
present, we employ FRG to identify a non- monotonous change of the gap
anisotropy in qualitative agreement with new experimental findings. From the
WRG, which is asymptotically exact in the weak coupling limit, we find an
s_{\pm}-wave to d-wave transition as a function of hole doping, complementing
previous findings from FRG [Thomale et al., Phys. Rev. Lett. 107, 117001
(2011)]. The gap anisotropy of the s_{\pm}-wave monotonously increases towards
the transition to d-wave as a function of x.
