This piece gets into nitty gritty details, so here’s a quick summary of what lies ahead:
- Claims you can find on the internet about specific “optimal” time windows for learning are misleading.
- The efficiency of different learning tasks may “peak” at different times during the day, so even at an individual level, there is no one optimal time.
- The best time to learn is essentially a time that works for you. In particular, this time should be within your normal waking hours.
- Building regular habits – a schedule for sleep and learning – is probably the best way to optimize your learning.
The last two points are critical. Rather than searching for a “scientifically proven” best time to learn, pick a time that suits you and charge ahead.
Cut Through the Noise
First things first. If you Google “best time of day for learning” or something similar, you might find some compelling pop-sci articles that simplify the answer to the point of absurdity. As far as I can tell, these articles are based upon a book that does break down some scientific research looking into associations between time of day and all kinds of cognitive parameters, like problem-solving ability, attentional control (focus), and yes, learning. The problem is that these articles yank an average time window out of the important context provided in the book. This time range is misleading and I won’t repeat it here to avoid perpetuating a falsehood.
This reminds me of one of my favorite expressions: “all models are wrong, but some are useful.” Reality is complex; we have to simplify it in order to understand. I don’t object to simplification in general, but I do object to this particular time-based simplification because it’s not useful. A more utilitarian model needs to account for variation between individuals and variation in the learning task at hand.
We’ve all heard about “early birds” and “night owls.” This categorization is another simplification, but it’s one that we can build off of. “Early birds” prefer to rise early and are more alert early in the day, whereas “night owls” prefer to stay up late and are more alert later in the day. In reality, it’s more of a distribution than two neat categories, but the essence of this model is useful. We have different preferences for sleep/wake cycles that are associated with subjective (self-reported) and objective (directly observable) measures of wakefulness, focus, and mental acuity that vary across the day.
So there are differences – sometimes large differences – between individuals in terms of their sleep/wake cycles and how alert and sleepy they feel across the day. There’s also plenty of research indicating that those individual variations are reliably associated with variation across the day in our capacity to perform tasks and learn. If you know anything about people, this is not surprising. We can even name the times of day at which we are most alert and able to focus. We can call those times our personal “peaks.”
For many cognitive tasks, our self-estimated personal peaks are reasonably accurate. Researchers call this “synchrony:” if you think you’re at your best in the morning, you perform better on many tasks in the morning. This includes tasks that involve memorizing facts (so-called “explicit learning” tasks), as well as tasks that require attentional focus. So far, it’s clear: performance peaks when we think it does. If only it were that simple!
Learning is an ensemble of different processes, it’s not just one thing. It includes memorizing facts, mastering procedures, and developing pattern recognition skills. For example, when we learn a language, we need to memorize new words, but we also need to learn the grammar of the language. We learn these things in different ways. Some pattern recognition and procedural learning happens automatically and unconsciously. This unconscious learning is often called “implicit learning,” in contrast with “explicit learning,” which refers to the practiced memorization of facts.
Here’s the kicker: some studies indicate that performance on implicit learning tasks is lower at our peak times and higher at our off-peak times. It’s the opposite pattern for explicit learning tasks. This is counterintuitive. One hypothesis to explain this phenomenon is that when we are most alert, the conscious mind actively suppresses unconscious learning processes. In other words, the optimal time of day for learning may depend on the learning task at hand.
What Can We Conclude?
We can see that there is a lot of variation between individuals in their sleep/wake cycles, these cycles are associated with predictable patterns of alertness and performance, and we can recognize these patterns in ourselves. That self-awareness can help us find the “best” time to complete some tasks, but not all tasks. So where does that leave us?
I look at it this way: given all of the nuance, variation, and complexity involved, it doesn’t make sense to worry too much about the best time of day to learn. It’s probably more important to find a time that works for you, meaning you’re able to focus without getting distracted. This can account for your schedule as well as your personal preferences: if you’re too sleepy to focus at a particular time, don’t study at that time.
To take it a step further, though sleep is critical for forming memories, don’t let a rough night of sleep stop you from studying the next day. Recent research suggests that subjective ratings of sleep quality are not associated with performance on many different cognitive tasks the following day, including learning tasks. That said, the feeling of sleepiness itself is a good indicator of reduced performance, so if you are feeling really tired, a 15-minute nap might be in order.
Last, but not least: don’t interpret any of this as an endorsement of all-nighters or sacrificing sleep for the sake of study! There are three compelling reasons to avoid all-nighters: you learn better during your normal waking hours, sleeping after you study helps to consolidate memories, and cramming is just not that effective for learning.
Let’s close with a simple rule of thumb: within your normal waking hours, if you’re not feeling very sleepy, it’s probably a good time to learn.