The Hogwarts Houses As...

Fears

Gryffindor: Phobophobia, the fear of fear. Gryffindors are brave people and also quite socially involved, and thus many will believe that fear makes them seem weak.

Hufflepuff: Monophobia, the fear of being alone. Hufflepuffs need the safety and comfort that comes from interpersonal interaction, and being alone would strip them of it.

Ravenclaw: Sedatephobia, the fear of silence. Ravenclaws need to communicate their ideas to properly fulfil them and discuss with others to create new ones, and without the means of vocal ability they would feel stupid and would think others would see them as less intelligent.

Slytherin: Atychiphobia, the fear of failure. Slytherins live for the glory and the feeling of winning, and the knowledge that someone else was better than them could cause extreme bouts of anger, jealousy and low self-esteem.