The textbook definition says that electron affinity is "the change associated with the addition of an electron to a gaseous atom."

When we go down a group, electron affinity should become more positive (less energy released), since the electron is added at increasing distances from the nucleus.

Understand that the atoms become larger as you go down a group. What I don't understand is what it means to have less energy released. Does this mean that it's easier to add an electron to a larger atom because it requires less energy for a negative ion to form?

Thought that it would be more difficult to add an electron to a larger atom because the core atoms shield the nucleus' positive charge. Thus since the nuclear charge is weaker in a larger atom, any electron coming near it won't want to bond as readily.