False fatigue is a Montessori phenomenon that takes place in every Montessori school around the globe. Montessori observed that, when left in freedom, children worked in a distinct cycle that was so predictable, it could even be graphed. This cycle, with two peaks and one valley, lasted approximately three hours. False fatigue typically occurs mid-morning, between 10:00-10:30am. The children seem to lose interest in work, behavior becomes disorderly, and the noise level rises. It may appear that the children are tired. At this time, many inexperienced Montessori teachers will ring a bell or flick the lights to call the children to whole group for songs or for outside time. Experienced teachers realize that this phenomenon is "false fatigue". They realize that the children will return to work on their own, and their work will be at an even higher level than before. The highest levels of focus and concentration take place during this second peak in the work cycle.
Although many Montessori teachers like to scurry observers out the door before false fatigue sets in, it would be beneficial for parents to observe this phenomenon. Parents might start to feel uneasy about the change in energy and noise level, but the children's true work begins during this peak after false fatigue.