Concept:
The effectiveness of a teacher is defined by their "Teaching Competency," which is a combination of knowledge, communication, and emotional intelligence. In pedagogical theory, these are categorized into cognitive, psychomotor, and affective domains. External physical attributes, while perhaps socially noted, do not contribute to the instructional quality or the cognitive development of the student.
Step 1: Analyzing Essential Cognitive Traits.
A teacher must serve as a reliable source of information. Good subject knowledge is the foundation of this role. Without it, the teacher cannot clarify doubts or provide depth to the curriculum. Furthermore, Good command over language is the primary vehicle for knowledge transfer; ideas remain locked if they cannot be articulated clearly.
Step 2: Analyzing Essential Affective Traits.
Education is a social interaction. Empathy towards children allows a teacher to understand the student's perspective, identify barriers to learning, and create a safe emotional space where students feel comfortable making mistakes and asking questions.
Step 3: Evaluating the Non-Essential Trait.
Having good looks is a superficial physical characteristic. It does not correlate with intelligence, empathy, or instructional skill. Therefore, it is a "non-functional" trait in the context of professional teacher-education requirements.