Understanding motivation through Content Theories

Content theories refer to a family of needs-based theories which aims to explain what motivates people as opposed to process theories which address how certain behavior is motivated. Maslow, Herzberg, Aldefer are the notable author of content theories. They all share an emphasis on growth, some emphasize on instinct, while all except Aldefer have little empirical evidences to support their theories. However experts have argued that it is unfair to dismiss their theories because they used questionnaires which is deemed inappopriate because it measures conscious explict motives rather than unconscious motives