Final answer:
Blaming poor performance on external factors exemplifies self-serving bias, which is the tendency to attribute successes to oneself and failures to outside situations, often seen in individuals with an external locus of control.
Step-by-step explanation:
Blaming one's poor performance on factors beyond control (external) is an example of self-serving bias. Self-serving bias explains our tendency to attribute success to internal factors, such as ability or effort, and failures to external factors, such as bad luck or difficult circumstances.
This bias serves to protect our self-esteem by allowing us to take credit for our accomplishments while deflecting blame for our failures. It also relates to the concept of locus of control, where individuals with an external locus of control tend to believe their outcomes are due to external forces beyond their control.