# If Oxygen has a lower electron affinity than Sulfur, then why doesn't sulfur has a lower electron affinity than selenium?

I've read that oxygen has a lower electron affinity (as shown the picture below), because it has a smaller atomic radius than sulfur and thus the electrons experience significant electron-electron repulsion.

However, I was wondering... Why is this not the case for sulfur and selenium or chlorine and bromine? Because of sulfur's and chlorine's smaller atomic radius compared to selenium and bromine, the incoming electron should also experience a slight electron-electron repulsion (just like it does with oxygen), so $$\ce{Se}$$ and $$\ce{Br}$$ should have a higher electron affinity.