Because she beat her goal this year by nearly 30 percent, Helena has been telling everyone in the sales department of her incredible skill as a salesperson. But last year when she didn't even reach her goal, she said her failure was due to the poor economy. Helena provides an example of

self-serving bias.

Explanation:

Self-serving bias is a cognitive trait that induces people to believe that the success achieved by doing something comes from internal factors such as self-effort, intelligence, insight. While when they perform negatively, they attribute to external factors such as economy, bad luck, influence from other people.