Final answer:
Alfred Adler is known for founding individual psychology and for proposing the superiority striving and inferiority complex concepts. He challenged Freud by focusing on social motives rather than sexual tensions and suggested that birth order impacts personality, with firstborns often becoming overachievers.
Step-by-step explanation:
Alfred Adler, a prominent figure in the field of psychology and a colleague of Sigmund Freud, is best known for founding the school of thought known as individual psychology. One common reason Adler challenged Freud's theories was his belief that feelings of inferiority, not sexual tensions, were the key motivators in human behavior. Adler introduced the concept of the inferiority complex, which he believed was a driving force in striving for superiority, influencing all of our thoughts, emotions, and behaviors. Adlerian theory also places great emphasis on social connections and the developmental importance of early childhood, viewing this period as critical for addressing and overcoming feelings of inferiority. Though Adler suggested firstborns are often driven to become overachievers to compensate for loss of attention due to siblings being born, this aspect of Adlerian theory, concerning birth order's influence on personality, has not been conclusively confirmed by subsequent research.