Which of the following is least likely to affect multitasking performance?

When considering factors that influence multitasking performance, the current emotional state is least likely to have a direct impact compared to the other options. Emotional states can affect attention, motivation, and cognitive load; however, they do not inherently change the ability to manage multiple tasks at once.

In contrast, task difficulty is crucial because more complex tasks may require more cognitive resources, making it harder to perform them simultaneously. Similarly, task similarity can affect performance since tasks that share cognitive resources or require similar skills can create interference, thereby impairing multitasking ability. Lastly, task practice plays a significant role as repeated exposure to tasks can lead to automaticity, which enhances performance when multitasking by freeing up cognitive resources.

Thus, while emotional states can influence our overall cognitive function, they are not as directly linked to the mechanics of multitasking as the other factors listed.