Final answer:
The nursing assistant is using rationalization as a defense mechanism to justify his tardiness by blaming heavy traffic instead of acknowledging the true reasons for his behavior.
Step-by-step explanation:
The nursing assistant who is frequently late for work and attributes the delays to heavy traffic is using the defense mechanism of rationalization.
Rationalization is a way to explain or justify behaviors or feelings in order to avoid the true reasons behind the actions. This assistant rationalizes his tardiness by blaming external factors, which allows him to avoid responsibility for his repeated lateness.
Rationalization is one of several defense mechanisms outlined by Freud, which work to reduce anxiety without the individual's conscious awareness.