While at Gateshead, Jane received food and shelter, taking care of the bottom layer of the pyramid. However, she didn't have the sense of safety; Mrs. Reed and her cousins would frequently abuse her and she often felt hated and depressed. As Ashe talks about in his criticism, Jane does find some friendship at Lowood, but it doesn't satisfy her because there she is deprived of nutrition. The Jane of Lowood is the product of an absolute lack of love and
affection, qualities critical to the healthy development of a growing
child.
As Jane gets older, going through life at Thornfield and Moor House, she climbs up the hierarchy of needs pyramid. She finds more love and belonging when she meets her cousins, and she becomes confident and self-respecting while being a teacher and after she has inherited money. This leads her to run back to Mr. Rochester, as she finds her life to have a purpose when serving him; purpose being the top of the pyramid.
As Ashe states: "Jane's happy ending must not be viewed merely as a proper or improper choice between right and wrong, but as the resolution of an intense psychological drama, wherein the degree of free will needed to make such a happy choice is finally attained." Jane finally finds her inner peace and is able to be happy.
Frederick L. Ashe, Jane Eyre: The Quest for Optimism, in Studies in the Novel, Summer, 1988, pp. 121-30. Reprinted in Novels for Students, Vol. 4.