Maslow's hierarchy is a psychological theory explaining levels of human needs. Physiological, safety, love, esteem, and self-realization are various levels mentioned in the theory.

A tree of life diagram for all flowering plant genera based on DNA analysis. (Image credit: Image by Zuntini et al., 2024, CC BY) All species on Earth, both living and extinct, are related.

Key points. Maslow’s "hierarchy of needs" is often presented as a five-level pyramid, with lower and higher needs. The four lower needs, if unmet, result in distress.

Maslow’s so-called "hierarchy of needs" is often presented as a five-level pyramid (pictured), with higher needs coming into focus only once lower, more basic needs have been met.

In 1943, psychologist Abraham Maslow came up with the hierarchy of needs, a ranking of what you have to have fulfilled in your life to reach self-actualization.