Basic Forms of Anxiety
In 1961 Riemann published a book called Grundformen der Angst [Basic Forms of Anxiety] in which he developed a typology of personality. He postulated that every person had two pairs of conflicting needs, each coming with their own form of fear or anxiety.
The first pair was the need to be an individual versus the need to be part of a group. The corresponding fears were fear of love and commitment and fear of loneliness and self-actualization. The second pair was the need for constancy versus the need for change. The corresponding fears were fear of insecurity and change, and fear of confinement and constancy.
Riemann stressed that everybody experienced all of these fears to varying extents. However, if one of the fears became so dominant within a person that it eclipsed the other fears, the person was mentally unhealthy.