Wednesday, July 20, 2011

Flexing the Muscle that is Self-Control

College was a busy time for me and by extension a trying period for my roommate Vanessa. Unlike the average 19 year old, Vanessa had assumed such adult-like habits as washing dishes directly after eating a meal, making regular trips to take out the trash, and refusing to live with scum and filth in general (God forbid). These healthy habits were by no means my own. I was just learning how to balance the demands of my two priorities: a heavy workload at NYU and a debaucherous social life. When I came home from a long day at the library I was overwhelmed and exhausted. The last thing I had time or energy for was cleaning up after myself. Instead I wanted to simply unwind and relax in preparation for a night out in New York. I drove poor Vanessa mad!

You might assume from this introduction, that Vanessa and I have long since parted ways; that my dirty habits so turned her off from a friendship with me, that when our first year together was over, she quickly moved on to greener and cleaner pastures. Surprisingly, that’s not the case at all. Vanessa and I continued to live together for the better part of college, and to this day remain extremely close friends. While much of that is due to our particular “chemistry,” some of it should be attributed to the evolution of my cleaning habits. As college wore on Vanessa taught me how to be a good roommate, and with repeated practice I became much more able to follow a day studying with a night cleaning. How was I able to build these roommate duties into a routine that was just as work heavy and party heavy as before? The answer is quite nicely explained by Roy Baumeister’s “strength model of self-control.” For a great summary check out Baumeister, Vohs, & Tice, 2007. Let me outline the basic components of this theory…

Self-control as a limited resource  According to the model, we each have a limited store of “energy” in our system that can be devoted to self-control – the ability to overcome impulsive responses or alter our behavior to bring it line with our ideals, morals, or social expectations. That means every time we engage in an act of self-control we use up some of this energy and thus have less energy available for, and perform worse on, future acts of self-control. Back to my example above, that I had used up all of my energy studying meant that I was unable to follow a day of heavy mental strain with an evening scrubbing and dusting.

Psychologists call this state of diminished resources following the exertion of self-control ego-depletion. The term “ego” was borrowed from Sigmund Freud’s theory on the anatomy of the mind. According to Freud it was the ego’s job to balance the desires of the id (which wants immediate pleasure and is motivated by sex and aggression) and the superego (which represents the moral and cultural standards of our society). So, after a day studying I was in a state of ego-depletion. I could no longer balance the desires of my superego (wanting my apartment to be clean for myself and my roommate) and my id (wanting to veg out on the couch and watch stupid television). My id won! 

What leads to ego-depletion?
As you saw above, a day studying at the library can lead to ego-depletion. This, however, is not the only way you get depleted. Baumeister and his colleagues have demonstrated that a variety of tasks lead to ego-depletion. In a typical study participants complete a first task that requires energy or effort, and must then complete a second task which also requires effort. In a state of ego-depletion from the first task participants perform worse on the subsequent task. Here are some examples (Baumeister, Bratslavsky, Muraven, & Tice, 1998; Muraven, Tice, & Baumeister, 1998).
1. Participants that were directed to suppress their emotions when watching a funny or sad movie clip were subsequently able to hold a handgrip for less time.
2. Dieters who were asked to give a speech in the laboratory subsequently ate more ice cream on an ostensible taste perception task.
3. Participants that were directed to suppress a forbidden thought were subsequently less able to stifle laughter in the second part of the study.
4. Participants who were directed to resist the temptation to eat chocolates and cookies and instead eat healthy radishes were more likely to give up on a frustrating task later on.

Is ego-depletion permanent?
So when I finished a long day of studying was I in a permanent state of ego-depletion? Were dieters who gave a speech never able to overcome their desire for ice cream again? Clearly no! Ego-depletion is a temporary state and over time that missing energy slowly repletes itself. That means after a night relaxing, or having fun in the city, I was again able to resume my work at the library the following day. In one study, Matthew Gailliot and colleagues even showed that ego-depletion could be overcome immediately – by drinking a glass of lemonade (Gailliot et al., 2007). The “energy” that underlies self-control is presumed to reflect glucose in the bloodstream. When we engage in self-control that glucose is converted to fuel for the brain and thus blood glucose levels temporarily go down. Drinking a glass of lemonade with sugar in it is presumed to restore blood glucose and thus the ability to engage in more self-control. Remember this when you are studying for midterms, or trying to get through the hours of the GRE or days of the Bar Exam.

Building up your energy stores
According to the "strength model of self-control," with repeated attempts at engaging in effortful behavior we can develop more of this energy in our system. With more energy we are able to engage in more and more self-control. As I previously mentioned, overtime Vanessa helped me to incorporate apartment cleaning into my already busy routine of studying and socializing. By asking me to take out the trash, or clean our toilet, Vanessa helped me to develop more self-control energy. In fact, neither my grades nor my social life suffered. It’s due to this phenomenon that Vanessa didn’t disown me as a friend and roommate!

The muscle analogy of self-control
All together, we can understand self-control using what psychologists call “the muscle analogy.” When we use our muscles to lift weights or exercise we use up energy and the muscles get tired out. Similarly, when we engage in short term attempts at self-control we also use up energy and our "self-control muscle" gets tired out. With physical exercise or mental exercise we need to take a break for that energy to return before we can use the muscle again. Overtime exercise builds up our physical muscles and allows us to use those muscles for longer and harder. In the same way, practicing effortful behavior builds up our "self-control muscle" and allows us to engage in more self-control.

Therefore, we must flex the muscle that is self-control. With Vanessa's help I did just that. Even if I was exhausted from a busy day, I still put my clothes away, and washed my dishes after one of our fabulous dinners. With practice it became part of my routine. I had more energy available to get it done. Vanessa, myself (and my current roommate) thank you!

What tasks do you find particularly ego-depleting? Have you witnessed your "energy" stores build up over time?

The article:
Baumeister, R., Vohs, K., & Tice, D. (2007). The Strength Model of Self-Control Current Directions in Psychological Science, 16 (6), 351-355 DOI: 10.1111/j.1467-8721.2007.00534.x


  1. I love this post. You always provide something that actually seems possible to work on for self-improvement! And thanks for the shout out! I think you give me way too much credit.

  2. Glad you find it useful (Vanessa). You definitely deserve the credit=)

    Keep reading!

  3. Great post! I'll definitely try this for college :)