In a recent post about the abilities and personality traits required to complete a PhD program, I mentioned the concept of executive function. From some of the responses I received, I gather that it’s an obscure and poorly understood concept that probably deserves its own post. So here we go.
To get the most important issue out of the way: Executive function does not mean ability to perform like an executive. Instead, it’s the ability, broadly speaking, to organize everyday tasks and to function in the world; the capacity to get done what you need to get done when you need to do so. I could write this out in detail, but instead I’ll quote you this AI overview written by Google Gemini, which is very much on point:1
Executive function refers to the mental skills and cognitive processes that allow people to plan, organize, manage time, control impulses, and achieve goals, essentially acting as the “management system of the brain.” Key components include working memory, cognitive flexibility, and inhibition. These skills are crucial for daily tasks, work, and social interactions, and are located in the brain's frontal lobe.
What Executive Function Does
Manages everyday tasks: It helps you plan and execute plans to get things done.
Problem-solving: It guides your ability to figure out and solve problems.
Attention: It allows you to focus and shift attention when needed.
Emotional control: It helps in managing and regulating emotions.
Key Components of Executive Function
Working Memory: The ability to hold and manipulate information in your mind.
Cognitive Flexibility: The ability to adapt your thinking and behavior to new situations and demands.
Inhibition: The ability to control impulses and stop inappropriate responses.
Why It Matters
Daily living: Good executive function helps you manage your daily life, including organizing, prioritizing, and staying on task.
Success in school and work: These skills are vital for learning, working independently, and completing large projects.
Mental well-being: Strong executive functioning contributes to a better quality of life and can help prevent issues like anxiety and depression.
When Executive Function is Challenged
ADHD: Attention-Deficit/Hyperactivity Disorder (ADHD) is often considered a disorder of executive functioning.
Daily struggles: People with impaired executive function may have difficulty focusing, following directions, managing time, and controlling impulses.
Supports: Strategies like using lists, creating routines, and organizing the environment can help individuals manage these challenges.
If you don’t have any issues with executive function, you may have read this and come to the conclusion that nearly any functioning adult must have good executive function. However, this is not the case. It is surprisingly common to see adults with some form of executive-function deficit. In particular, people on the Autism spectrum, who may be very intelligent and capable otherwise, frequently struggle with executive function.
In my work educating PhD students, I have worked with several students who struggled with executive function. This experience has led me to identify certain behavior patterns that are common among such students. One is not preparing sufficiently or appropriately for meetings or presentations. For instance, when such students give lab meeting presentations, their slides often look hastily put together, some parts are missing, slide quality varies widely throughout the slide deck, and there’s the inevitable sudden ending where the student ran out of time to prepare the final part of the talk. Another is not completing simple tasks I ask them to do. For instance, I may ask a student to read a specific paper and the next time I meet with them they haven’t read the paper but may have done all sorts of other things instead. I then ask them to please read the paper for our next meeting, and when that meeting comes around they still haven’t read the paper. And it goes on like this for weeks until eventually neither the student nor I remember why it would have made sense to read the paper in the first place.
There’s a curious observation I’ve made working with people who struggle with executive function. My natural instinct is to requests increasingly simpler tasks, but it often doesn’t help. For example, I may ask a student to do a literature review on a certain topic, and the next time we meet they haven’t done it. So then I ask them to start by reading five specific papers. The next time we meet they haven’t done it. Then I ask them to read just one paper and write a one-paragraph summary on it. The next time we meet they still haven’t done any of it. Every week, instead, they have done something else entirely. And the simpler and smaller I make the requested task, the less inclined the student seems to be to actually complete it. It’s a difficult position to be in as an advisor, as the student doesn’t do well performing large, complex tasks, but also doesn’t respond well to me trying to simplify things and reduce scope.
I have a vague notion of what may be happening in these situations: Students look at the entirety of the tasks they need to work on and discount all the items that are easy, that they know they could do relatively quickly if they actually worked on them. In their minds, because those tasks are easy, they are essentially done already. So, instead of doing those tasks, the students focus on the most difficult possible thing they could be working on, and try to make progress on that one.2 Of course, the most difficult possible thing to work on is usually too difficult for the students to actually accomplish, while the easier tasks don’t get done because they aren’t given sufficient attention or started at all. And the simpler I make the tasks I ask students to do, the lower my requests rank in the students’ internal priority ranking of things to tackle.
If you’re a student and reading this rings true to you, I’d like to ask you to consider that even simple tasks need doing and require a finite amount of time for completion. So please be honest with yourself about how long simple tasks will take and don’t wait until the last minute as you will run out of time. If you’re an advisor working with students who have some executive-function deficit, I’m not sure what to recommend. I have not found the ideal approach to managing such students. I still think breaking larger projects into increasingly simpler tasks has to be part of the solution, but maybe it needs to be accompanied by honest discussions about how long individual tasks should take, how to schedule tasks when we can roughly estimate how much time they will require, what the specific reasons are that keep students from tackling certain tasks, and so on.
To end on a positive note, I’d like to emphasize that it’s absolutely possible to be successful in life even with impaired executive function. At least four of my past PhD students have struggled with executive function and all but one of them managed to complete their PhD. Today they are successful in careers appropriate for their training, be it academia or industry. To any of my readers who may have difficulty with executive function, know that recognizing your limitations is the first step towards working around them. You can develop strategies and routines that help you get things done on time and in an organized manner, even if it doesn’t come naturally. We all have various strengths and weaknesses, and we need to learn how to work around our weaknesses while taking advantage of our own unique strengths.
Yes, the text in the quote is AI generated. That’s why it’s in a quote. I did not write it myself.
The reasoning is, presumably, that the most difficult thing the student could work on is the primary barrier that keeps the student from completing the entire project. Once this issue is resolved, the thinking goes, the rest of the project will easily fall into place.
Claus, fellow professor here. I know you’re trying to help, and I’m saying this with all due respect: parts of your post land as demeaning and shaming to the very students you want to support. I suggest a different playbook.
Improving executive function doesn't boil down to “doing what you’re told, but smaller.” For many neurodivergent students (PhD candidates and undergraduates alike), the bottlenecks are time perception, salience, and working memory. Time blindness means the world collapses into two buckets: now and not-now. “Read one paper and write a paragraph” feels trivial, so it slides into not-now until a hard trigger makes it suddenly now, usually too late. Working-memory limits add an object-permanence effect: if the task isn’t literally in front of me—almost always better in analog rather than digital form—it may as well not exist. On top of that, ADHD is an interest-based nervous system: activation turns on with novelty, challenge, degree of interest, or immediate social consequence. That’s why students often jump to the most challenging part first; paradoxically, it’s the one that finally flips the “on” switch.
This is also why “break it into simpler tasks” often backfires. Shrinking scope without changing time, salience, or visibility lowers meaning (“trivial → not-now”), multiplies context switches, and creates shame loops (“I couldn’t even do the small thing”). If you want different results, change the environment, not just the size of the chores.
There’s also a real upside to neurodiversity that I think you’re missing. Many neurodivergent individuals are big-picture thinkers, capable of rapid association, systems-level synthesis, and deep hyperfocus when their level of interest or novelty is high. There are plenty of highly successful, neurodivergent people out there who just have different wiring, which has real advantages in the proper context.
Also, no need to reinvent the wheel. You’re not a psychologist, and you don’t need to be. Neurodivergent students benefit from licensed coaching and evidence-based supports. At UT, Longhorn TIES provides neurodiversity training for faculty and staff, as well as direct student support. Take the training and point students there: https://longhornties.utexas.edu/
Some minor changes in mentoring neurodivergent students can go a long way. Instead of “I simplified the tasks and they still failed,” try “Let’s co-design conditions that make time visible, tasks present, and outcomes meaningful.” That framing maintains dignity and enhances performance.
Prepared with ChatGPT 5 (GPT-5 Thinking) based on my prompts and revised.
Tom
Do you have any tips that have helped your students overcome cognitive inflexibility, in particular? I'm fine on other points, but my mental flexibility is bad. Even if I care about a project and have identified the next step to take, my mind may simply refuse to work on it. I can push through the mental block, but it drains my energy too much if I do that regularly, so my long-term productivity suffers either way.