It's notable that in the various parent-child relationships presented in King Lear, it's the children who display greater maturity than their parents. The most obvious example, of course, would be Lear's daughters. Regan and Goneril understand immediately the full import of their father's foolish decision to divide his kingdom between them and their sister Cordelia. They know that as soon as Lear gives up his kingdom, his power and authority will start draining away.
For her part, Cordelia shows a rather different kind of maturity. In refusing to make a public profession of love for her father, she's effectively telling everyone that she'll have nothing to do with such a silly, childish charade. No longer daddy's little girl, Cordelia is now very much a woman in her own right.
Then there is the immaturity of Gloucester, so easily seduced by the lies and deceit of Edmund, who expertly turns him against his legitimate son, Edgar. As with Lear, Gloucester is so childishly insecure that he desperately needs to feel the love, and Edmund is only too willing, for purely ulterior motives, to make him feel it—just as Regan and Goneril professed their love for Lear to get their greedy hands on his kingdom.