This emoji was part of the proprietary / non-standardized emoji set first introduced by Japanese carriers like Softbank. These emojis became part of the Apple iPhone starting in iOS 2.2 as an unlockable feature on handsets sold in English speaking countries.
Maslow's (1943, 1954) hierarchy of needs is a motivational theory in psychology comprising a five tier model of human needs, often depicted as hierarchical levels within a pyramid. Maslow stated that people are motivated to achieve certain needs and that some needs take precedence over others.
Maslow studied psychology at the University of Wisconsin and Gestalt psychology at the New School for Social Research in New York City before joining the faculty of Brooklyn College in 1937. In 1951 he became head of the psychology department at Brandeis University (Waltham, Massachusetts), where he remained until 1969.