Materialism is a philosophical theory that suggests that the only thing that truly exists is physical matter. This perspective asserts that all phenomena, including thoughts, feelings, and consciousness, can ultimately be explained in terms of physical processes in the brain. Materialism can also refer to an emphasis on material possessions and wealth as key indicators of success or happiness in life. In sociology, materialism can refer to the prioritization of material concerns over social or cultural values. In psychology, materialism can refer to an individual's tendency to prioritize material possessions and wealth over other aspects of life satisfaction.