Effective learning follows the One Hour Rule of memory, a rule discovered over a hundred years ago but only recently validated in neuroscience.1
Researchers discovered this in a learning experiment that separated learners into three groups.
- The first group memorized a list of nonsense words. The next day, everyone could recall the list of words.
- The second group memorized the same list but then immediately learned a second list. The next day they couldn’t remember either list.
- The third group memorized the list, took a two-hour break, then studied the second list. They recalled the first list of words the next day, no problem.
The researchers concluded it takes an hour or so for memories to become fixed in the brain. Disruptions and distractions in that one hour period swept the memory clear.
Neurobiologists eventually learned the science behind this experiment: long-term memory is literally grown in the brain. The brain creates new branch connections between brain cells, a process that requires brain food and enough time for these branches to grow. Our mind is more botanical than mechanical, more like a plant than a computer. Memories grow in the mind over time.
This means learning must be spread out and reinforced to be effective. When we try to learn too much in too little time, we lose it all. Cramming doesn’t work. Back-to-back seminars and all-day classroom sessions aren’t very effective. Without a distributed learning approach that reinforces learning with repeated experience, information is swept from the mind. It all goes in one ear and out the other.
1Nicholas Carr, The Shallows: What the Internet is Doing to Our Brains (New York: W.W. Norton & Co., 2010), p. 183-4.