Final answer:
The officer's initial assumption follows the labeling theory based on stereotypes, but upon understanding Irene's context, the officer exercises discretionary justice and empathy, which results in just a warning.
Step-by-step explanation:
The psychological theories explaining the officer's initial and final judgments are, respectively, labeling theory and discretionary justice. Labeling theory suggests that people interpret and label behaviors based on biases and stereotypes. Initially, the officer assumes Irene is an irresponsible teenager, reflecting a stereotype. However, after hearing her explanation, the officer uses discretionary judgment, considering the context and deciding that her behavior is understandable in the circumstances, which leads to the officer giving Irene a warning instead of a ticket. This change of decision can also be linked to cognitive empathy, where the officer puts himself in Irene's position and understands her reason to speed.