Final answer:
Jim's conclusions about his own and Sam's failed tests are an example of the actor-observer effect, where personal failures are attributed to external factors, while others' failures are attributed to their character or actions.
Step-by-step explanation:
Jim's judgments can be best explained by the actor-observer effect. This effect occurs when a person attributes their own failures to external, situational factors while attributing others’ failures to internal, dispositional factors. When Jim fails his math test, he blames the difficulty of the test rather than his own ability or study habits. In contrast, he attributes Sam's failure in biology to Sam not studying hard enough, overlooking any situational factors that might have contributed. This bias demonstrates our tendency to give ourselves more leniency for our shortcomings while holding others to a stricter standard.