Sarah habitually makes nasty, hostile comments about her teachers. freud would have suggested that her behavior illustrates the powerful influence of the:

The answer is "id".

The id refers to the primitive and instinctual segment of personality. The id is the incautious (and oblivious) some portion of our mind which reacts specifically and instantly to the senses. The identity of the infant youngster is all id and just later does it build up a ego and super-ego. The id takes part in essential process thinking, which is crude, silly, nonsensical, and dream arranged.