Work That's Too Hard
There's a lot of pressure for kids to learn more and more and at younger ages than in past generations. For example, while a few decades ago kindergarten was a time for learning letters, numbers, and basics, most kindergarteners today are expected to read. With test scores being heavily weighted and publicly known, schools and teachers are under great pressure to produce high test scores; that pressure can be passed on to kids.
Work That's Too Easy
Just as it can be stressful to handle a heavy and challenging workload, some children can experience stress from work that isn't difficult enough. They can respond by acting out or tuning out in class, which leads to poor performance, masks the root of the problem, and perpetuates the difficulties.
Learning Styles Mismatch
You may already know that there are different styles of learning -- some learn better by listening, others retain information more efficiently if they see the information written out, and still others prefer learning by doing. If there's a mismatch in learning style and classroom, or if your child has a learning disability (especially an undiscovered one), this can obviously lead to a stressful academic experience.
Kids are being assigned a heavier homework load than in past years, and that extra work can add to a busy schedule and take a toll.
Many of us experience test anxiety, regardless of whether or not we're prepared for exams. Unfortunately, some studies show that greater levels of test anxiety can actually hinder performance on exams. Reducing test anxiety can actually improve scores.