The concept, proposed by the psychologist the Abraham Maslow (1908-1970), that all human needs can be ranked in the order that people seek to satisfy them, and that this order forms a motivational hierarchy. According to Maslow, the needs, in ascending order of importance, are: physiological needs, need for safety, need for love and belonging, need for self-esteem and recognition, and the need for self-actualization. Coaches are mainly concerned with enabling their athletes to fulfil the higher needs. Maslow's concept implies these higher needs can only be achieved when the lower needs, such as the fundamental physiological need for food and shelter, have been met.