What are some possible causes of performance deficiencies other than a need for training?

Whether we are speaking of performance deficiencies in school, on the job, or in the world of the arts, there are many other reasons aside from a lack of training.  One is distraction, such that a worker, a student, or a dancer is unable to perform optimally because the environment is noisy, crowded, or offers a tempting distraction such as an open window to gaze out of.  Another reason for performance deficiency is hunger. This...

Whether we are speaking of performance deficiencies in school, on the job, or in the world of the arts, there are many other reasons aside from a lack of training.  One is distraction, such that a worker, a student, or a dancer is unable to perform optimally because the environment is noisy, crowded, or offers a tempting distraction such as an open window to gaze out of.  Another reason for performance deficiency is hunger. This is the rationale behind providing breakfast for students and why some employers will provide a cafeteria or vending machines and at the very least, give people lunch and snack breaks. None of us is at the top of our game when we are hungry. Tiredness is another reason we might not perform well.  I was recently in the hospital and learned that nurses frequently work twelve hour shifts and are sometimes "held over" for even longer hours when someone calls off.  It seems unlikely that working hours like this is conducive to doing one's best work, and there is research that bears this out.  Emotions can also interfere with our performance.  A person who is angry or frightened finds it difficult to do a very good job. Positive emotions can pose similar difficulties. The person who has just fallen in love might have a hard time focusing on the demands of the job, the classroom, or a performance.  Finally, performance can be harmed by a lack of motivation or challenge.  Those who are disaffected and disengaged are not going to perform nearly as well as those who are motivated, internally or externally, and challenged by the requirements of the task.  Certainly, training people to do their respective jobs properly is important, but it is by no means the only reason for performance deficiencies.