People sort things into hierarchies all the time, from grouping animals into species to putting files in folders. It's a big part of how we make sense of things, and it explains why a nested task list feels easier to work with than a flat one.
How we organise information
Mental models
We understand the world by building mental models of it, and cognitive psychology research has found that those models tend to be hierarchical: broad categories at the top, specific details underneath.
Working memory
Working memory only holds a little at once. George Miller's well-known "7 ± 2" paper suggested we can keep roughly 5 to 9 items in mind at a time. Grouping information into chunks gets around that limit, and a hierarchy is chunking you can see.
Why it suits task lists
Breaking things down
Faced with a big project, most people's first move is to split it into parts. Doing that on paper takes the anxiety out of a large project and gives you a better sense that you're in control of it.
Small wins
Finishing a task releases dopamine, which is where the sense of achievement comes from. A hierarchy gives you more of those moments, because you can see progress at several levels: a subtask done, then a group of subtasks, then a milestone.
What you get out of it
Less to keep track of
When the structure is written down, you aren't spending effort remembering it. That leaves more attention for the task in front of you and makes decisions about what to do next easier, and it's less stressful.
Motivation
Seeing how a small task connects to a bigger goal makes it more motivating. Clark Hull's goal-gradient hypothesis describes a related effect: the closer we think we are to a goal, the harder we work towards it.
Getting unstuck
Too many choices
With too many options in front of you, it's easy to freeze. A hierarchy gives you an obvious place to start, puts things in a rough order, and lets you look at one level at a time.
Feeling overwhelmed
A big project broken down feels more manageable. You can see the next concrete step, and as branches get ticked off, you can see how far you've come.
Putting it into practice
Build it up slowly
You don't need a perfect hierarchy on day one. Start with a few top-level categories and add detail as you go, working from general to specific.
Expect it to change
Your understanding of a project changes as you work on it, so the tree should too. In Tatask you can drag a task, along with everything under it, to wherever it now belongs.
If you'd like a list that works with how you already think, try Tatask free for 30 days.
References:
- Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information.
- Hull, C. L. (1932). The goal-gradient hypothesis and maze learning.