Which characteristics are not of good mental health?

In educational psychology (as used in TET/pedagogy syllabi), "good mental health" is defined by a cluster of positive traits — a well-regulated, routine life, emotional maturity, self-confidence, tolerance, acceptance of reality, and the ability to honestly evaluate oneself. Withdrawing into isolation or being excessively self-effacing runs counter to this cluster of traits.

Checking each listed pair against this framework: a regulated life with emotional maturity, self-confidence with tolerance, and acceptance of reality with self-evaluation ability are each hallmark markers of psychologically healthy functioning. Confining oneself away from others to an excessive degree, however, reflects social withdrawal and reduced environmental engagement rather than healthy adjustment.

Cross-checking each pair against the criteria for good mental health:

• Regular life, emotional maturity — reflects stable self-regulation; a marker of healthy adjustment.

• Self-confidence, tolerance — reflects settled self-worth and openness to others; a marker of healthy adjustment.

• Acceptance of reality, self-evaluation ability — reflects a realistic, well-adjusted outlook; a marker of healthy adjustment.

• Too humble, confined to oneself — reflects social withdrawal and reduced engagement with one's environment, not healthy adjustment.

Since three of the four pairs describe established markers of good mental health, the pair describing withdrawal — "Too humble, confined to oneself" — is the one that is not a characteristic of good mental health.