Our Draining Willpower in the Digital Age?

Quick, say the colors of the following words out loud: BLUE, ORANGE, GREEN, PURPLE, PINK, YELLOW. How many did you get right? And what does this have to do with willpower? Psychologists use this kind of test to measure our current level of willpower.1 The speed and accuracy of your responses reflects your level of willpower or self-control.

While willpower has long intrigued psychologists, groundbreaking research in recent years has changed our basic understanding of it. Psychologists now say that willpower depends on a limited but replaceable source of energy.1 According to this idea, known as ego depletion, our willpower becomes drained as we work through demanding tasks and decisions. This new understanding of willpower comes at a time when technology is redefining our experience of willpower.

Closely related to ego depletion is decision fatigue – the idea that we make poor decisions when willpower runs low. The effects of decision fatigue can be startling. A well-known study of parole appeals found that prisoners’ chances of gaining parole fluctuated wildly over the course of the day.2 At the beginning of the day, judges granted parole to prisoners 65 percent of the time. Several hours later they granted parole to only about 10 percent of prisoners. The rate shot back up to 65 percent right after lunch and dinner breaks.

This unnerving pattern can be explained by glucose concentrations in the brain. Researchers suggest that willpower relies on glucose as a limited energy source, rising and falling with glucose levels.3 The judges were receiving a burst of glucose from meals, but the mental work of analyzing case after case gradually depleted their reserves. Similar effects have been witnessed in many psychological experiments. In one experiment, subjects drank regular or diet lemonade and then performed a decision task.4 The people who drank sugar-free lemonade were much more likely to make impulsive decisions. Because of lower glucose levels, they displayed a diminished ability to engage in effortful decision-making processes.

Experiments like this have led some psychologists to describe glucose as a sort of brain fuel for willpower. While this biochemical account of willpower appeals to us for its reductionist explanation, it carries unsettling implications. It seems to absolve us of blame for lapses in self-control. Is it really my fault if I fail to resist delicious cupcakes, or do something worse?

Perhaps it is. Recent experiments indicate that cognition heavily influences willpower. Specifically, our beliefs about willpower – whether we conceive of it as biologically limited or not – immensely influence our self-control.5 Researchers at Stanford University examined people’s beliefs about willpower prior to subjecting them to a battery of self-regulation tasks. People who viewed willpower as biologically limited displayed substantially less self-control than those who viewed willpower otherwise. The phenomenon extended outside of laboratory experiments to long-term behaviors like dieting. The researchers assert that ego depletion depends on our implicit theories of willpower, rather than glucose concentration. While these results do not necessarily conflict with the limited energy model, they demonstrate that willpower cannot be reduced to mere glucose concentrations.

While the scientific understanding of willpower expands, our daily experience of it continues to evolve. We have to exercise self-control in response to new stimuli. We grapple with tempting influences like YouTube that did not exist prior to the Web. Willpower is after all a relatively modern notion: Google’s Ngram viewer shows that use of the word took off starting around 1960.6 YouTube, along with companies like Facebook and Amazon, continue to expand rapidly. YouTube now streams over four billion videos every day.7

YouTube targets users’ willpower through its advertising and content presentation. Much like a supermarket, YouTube’s interface barrages users with choice. Go to a typical video page and there are nearly 30 links to promoted and related videos. Finish watching a video and the screen flutters with 12 more links. The temptation to watch additional video and sheer amount of choice facilitate ego depletion and decision fatigue. Ego depletion makes it harder to leave the website and attend to other priorities.

Companies and marketers have a strong incentive to present their advertising and content in ways that weaken their audience’s willpower. But media sites like YouTube are uniquely positioned to target their users’ willpower – the amount of choice they present is virtually unlimited. While the typical supermarket carries around 50,000 distinct products,8 the presentation of choice remains limited by physical factors. YouTube, on the other hand, can create dynamic and interactive experiences that target users’ willpower more selectively. Personalized content is huge here. YouTube and many other websites harness personal data to tailor content to our interests. Personalized content is more tempting than plain content and more effectively challenges our self-control.

Willpower remains an elusive animal. And expanding access to YouTube and other technologies continue to reshape our everyday experience of willpower. But research in the last several years has greatly developed our understanding of willpower, enabling us to get a better sense of our impulses. Can future findings reconcile the limited energy model with the evidence that willpower stems from cognition? Should we regard willpower as something controlled by brain chemistry or shaped by mindset? In any case, our experience of willpower will continue to evolve with technological change – and so will our scientific understanding.


  1. Gailliot, Matthew T., and Roy F. Baumeister. “The Physiology of Willpower: Linking Blood Glucose to Self-Control.” Personality and Social Psychology Review 11 no. 4 (2007): 303-27.
  2. Danziger, Shai, Jonathan Levav, and Liora Avnaim-Pesso. “Extraneous Factors in Judicial Decisions.” Proceedings of the National Academy of Sciences 108 no. 17 (2011): 6889-92.
  3. Gailliot, Matthew T., Roy F. Baumeister, C. Nathan DeWall, Jon K. Maner, E. Ashby Plant, Dianne M. Tice, Lauren E. Brewer, and Brandon J. Schmeichel. “Self-Control Relies on Glucose as a Limited Energy Source: Willpower Is More Than a Metaphor.” Journal of Personality and Social Psychology 92 no. 2 (2007): 325-36.
  4. Masicampo, E.J., Roy F. Baumesiter. “Toward a Physiology of Dual-Process Reasoning and Judgment: Lemonade, Willpower, and Expensive Rule-Based Analysis.” Psychological Science 19 no. 3 (2008): 255-60.
  5. Job, Veronika, Carol S. Dweck, and Gregory M. Walton. “Ego Depletion—Is It All in Your Head?” Psychological Science 21 no. 11 (2010): 1686-93.
  6. Google Ngram Viewer. Accessed February 2, 2012. http://books.google.com/ngram
  7. Oreskovic, Alexei. “YouTube hits 4 billion daily views.” January 23, 2012. Accessed February 1, 2010. http://www.reuters.com/article/2012/01/23/us-google-youtube-idUSTRE80M0TS20120123
  8. “Supermarket Facts.” Food Marketing Institute. Accessed January 24, 2012. http://www.fmi.org/facts_figs/?fuseaction=superfact
  9. “Just Another Computer Addict.” Flickr. February 2, 2010. Accessed February 14, 2012. http://www.flickr.com/photos/peter-repeater/4325173849/
  10. “What Makes Apple Apple. Digital image.” Flickr. December 22, 2011. Accessed February 14, 2012. http://www.flickr.com/photos/opensourceway/6555465931/in/photostream

Michael Begun is a second-year student at the University of Chicago majoring in computer science and minoring in linguistics. Follow The Triple Helix Online on Twitter and join us on Facebook.