Habits, and not Willpower or Self-control are Responsible for Resisting Temptation and Sticking to Positive Productive Behaviours

Habits, and not Willpower or Self-control are Responsible for Resisting Temptation and Sticking to Positive Productive Behaviours 

Brian M. Galla and Angela L. Duckworth
University of Pennsylvania

Abstract

Why does self-control predict such a wide array of positive life outcomes? Conventional wisdom holds that self-control is used to effortfully inhibit maladaptive impulses, yet this view conflicts with emerging evidence that self-control is associated with less inhibition in daily life. We propose that one of the reasons individuals with better self-control use less effortful inhibition, yet make better progress on their goals is that they rely on beneficial habits. Across six studies (total N = 2,274), we found support for this hypothesis. 

In Study 1, habits for eating healthy snacks, exercising, and getting consistent sleep mediated the effect of self-control on both increased automaticity and lower reported effortful inhibition in enacting those behaviors. 

In Studies 2 and 3, study habits mediated the effect of self-control on reduced motivational interference during a work-leisure conflict and on greater ability to study even under difficult circumstances.

In Study 4, homework habits mediated the effect of self-control on classroom engagement and homework completion. 

Study 5 was a prospective longitudinal study of teenage youth who participated in a five-day meditation retreat. Better self-control before the retreat predicted stronger meditation habits three months after the retreat, and habits mediated the effect of self-control on successfully accomplishing meditation practice goals. 

Finally, in Study 6, study habits mediated the effect of self-control on homework completion and two objectively measured long-term academic outcomes: grade point average and first-year college persistence. 

Collectively, these results suggest that beneficial habits--perhaps more so than effortful inhibition--are an important factor linking self-control with positive life outcomes.

…we must make automatic and habitual, as early as possible, as many useful actions as we can…The more details of our daily life we can hand over to the effortless custody of automatism, the higher mental powers of mind will be set free for their own proper work.

~William James

The Principles of Psychology, 1890

…when I first started working with Tracy [personal trainer], finding motivation was hard. She advised me to think of exercise as an automatic routine, no different from brushing your teeth, to avoid getting distracted. Now it is part of my life - I exercise Monday to Friday at 10am and always stick with it.

~Gwyneth Paltrow

Interview with The Telegraph, 2013

Self-control is defined as the ability to voluntarily regulate attention, emotion, and behaviour in the service of more valued goals. The benefits of self-control are now well-documented. It predicts better academic performance (Duckworth & Carlson, 2013), higher earnings (Moffitt et al., 2011), better physical health (Moffitt, et al., 2011), and better social relationships (de Ridder, Lensvelt-Mulders, Finkenauer, Stok, & Baumeister, 2012; Tangney, et al., 2004). So it is little surprise that some psychologists have called self-control the “greatest human strength” (Baumeister & Tierney, 2011).

How do individuals with better self-control manage to stick to their goals? This question has received surprisingly little attention outside of laboratory studies. Thus, very little is known about how, exactly, individuals with better self-control fulfill long-term aspirations. The most obvious explanation is that self-control enables “in the moment” inhibition of maladaptive impulses. Recent studies call this view into question: Better self-control is, paradoxically, associated with less inhibition of immediately available temptation (Hofmann, Baumeister, Förster, & Vohs, 2012; Imhoff, Schmidt, & Gerstenberg, 2013). Across six studies, we test the hypothesis that one of the reasons individuals with better self-control use less effortful inhibition and correspondingly make better progress towards their goals, is because they rely on beneficial habits.

Effortful Inhibition and its Limitations

Just say no! Just do it! From drug prevention campaigns to sports ads, the term self-control—and its most common synonym, willpower—conjures images of using brute force to align behavior with valued goals. Indeed, it is intuitive to liken self-control to a muscle that must be flexed in order to inhibit maladaptive impulses in the heat of the moment (Baumeister, Vohs, & Tice, 2007; Muraven & Baumeister, 2000). The connotations of effortful inhibition inherent in the very language of “willpower” do have some empirical justification. Studies show, for example, that self-report and informant-report ratings of self-control are modestly correlated with performance on executive function tasks that require withholding a prepotent but maladaptive response (Duckworth & Kern, 2011; Sharma, Markon, & Clark, 2014).

Though the capacity to effortfully inhibit maladaptive impulses is advantageous, doing so can lead to failures of self-regulation in a subsequent situation (Baumeister, Bratslavsky, Muraven, & Tice, 1998; Hagger, Wood, Stiff, & Chatzisarantis, 2010). In addition, effortful inhibition can be impaired by common everyday experiences, including fatigue (Hagger, et al., 2010), engaging in cognitively demanding tasks (Schmeichel, Vohs, & Baumeister, 2003), prior decision-making (Vohs et al., 2008), rumination (Denson, Pedersen, Friese, Hahm, & Roberts, 2011), and stress (Glass & Singer, 1972; Oaten & Cheng, 2005). Effortfully inhibiting impulses is also prone to backfiring. That is, suppressing an unwanted impulse can, ironically, make it more likely to influence behavior. In one demonstration of this effect (Johnston, Bulik, & Anstiss, 1999), female participants were first asked to spend five minutes putting together a hypothetical dessert menu. Participants assigned to a suppression condition were asked to “try not to think about chocolate” while completing the task. As expected, suppression was helpful in reducing chocolate-related thoughts: Participants in the suppression condition mentioned chocolate less often than participants in a no-manipulation control condition. However, participants asked to suppress thoughts of chocolate ended up earning more chocolates on a subsequent work task than individuals who were not asked to suppress their thoughts.

The unreliability of effortful inhibition suggests that the adaptive value of self-control for fulfilling long-term goals extends beyond single acts of inhibiting maladaptive impulses (Fujita, 2011). Indeed, this possibility is supported by a recent experience sampling study of daily temptation (Hofmann, et al., 2012). In this study, approximately two hundred adults provided momentary reports of desire strength, motivational conflict, attempts to inhibit temptation, and behavioral enactment. Consistent with the idea that self-control supports positive life outcomes through means other than effortful inhibition, individuals with better self-control were less likely to report attempts to inhibit temptation than were individuals with lower self-control. 

Building on this research, we propose that one of the reasons individuals with better self-control use less effortful inhibition, yet make better progress on their goals is that they rely on beneficial habits. Of course, the possibility that habit might explain the association between self-control and positive life outcomes assumes that in daily life, behaviors that align with enduringly valued goals are by nature feasible to execute routinely and in manner that is conducive to habit formation. As such, we first provide a brief overview of habit and its relation to goal adherence.

Habit and Goal Adherence

Habits are automatic response tendencies that are triggered by contextual cues (Lally, Van Jaarsveld, Potts, & Wardle, 2010; Neal, Wood, & Quinn, 2006; Ouellette & Wood, 1998; Verplanken, 2010; Wood & Neal, 2007). Habits are formed via the gradual development of mental associations between a frequently repeated behavior (e.g., buckling a seatbelt) and recurring situational cues (e.g., getting into a car) (Lally, et al., 2010; Wood & Neal, 2007). Once these associations are forged, perceiving the appropriate cues will automatically retrieve the response from memory and trigger an impulse to initiate it. For example, habitual popcorn eaters consume more stale popcorn in a movie theater but not in a conference room (Neal, Wood, Wu, & Kurlander, 2011), presumably because conference rooms do not provide the appropriate triggering cues associated with previous popcorn consumption. Many common experiences are seemingly guided by habits: Experience sampling studies indicate that nearly 50% of behaviours are repeated in the same circumstances almost every day (Wood, Quinn, & Kashy, 2002).

Habits are not mediated by active mental representations of goals (Dickinson, 1985; Wood & Neal, 2007). This is to say that once habits are formed, they are enacted even in the absence of conscious intent (Ouellette & Wood, 1998). For example, Ji and Wood (2007) showed that intentions to buy fast food actually predicted buying fast food only for individuals with weak fast food habits. Among individuals with strong fast food habits, however, intentions did not predict behavior. Thus, for habits, what we tend to do in the present is what we have tended to do in the past whether we intend to do so or not.

Goal-independent automaticity explains why bad habits are so pernicious—they lock people into patterns of maladaptive behavior despite better intentions. Yet this very same mechanism also explains why beneficial habits can be advantageous—they lock people into adaptive patterns of behavior. William James (1899) famously contended that “our virtues are habits as much as our vices” (p. 64). Because they are triggered automatically by contextual cues, beneficial habits and routines can function to remove numerous impediments to goal pursuit. Habits are not disrupted by lapses of attention (Botvinick & Bylsma, 2005; Wood, et al., 2002), changes in motivation (Dickinson, 1985), stress (Schwabe & Wolf, 2009), or impairments in effortful inhibition (Neal, Wood, & Drolet, 2013). Beneficial habits may also help to circumvent the supporting cognitions (“Do I really have to do this now?”) and justifications (“I can do this later.”) that give license to avoid carrying out effortful, goal-relevant activities. Freed from the burden of having to effortfully inhibit these interfering thoughts and conflicting motivations, individuals with beneficial habits should be better able to remain more loyal to their enduringly valued goals.

The relation between habits and goal adherence is anecdotally appreciated in the biographies of notable writers, artists, musicians, and athletes (Currey, 2013). Anthony Trollope—author of over 50 books—wrote three thousand words every day starting at 5:30am before heading to his postal service job; the Nobel Prize-winning poet, Maya Angelou, wrote from about 7:00am to 2:00pm in the same rented hotel room. Kellogg (1994) argues in Psychology of Writing that these routines are conducive to productivity:

 “The room, the time of day, or ritual selected for working may enable or even induce intense concentration or a favourable motivational or emotional state” (p. 186). 

The utility of such habits and routines is bolstered by research showing that elite violin students—rated by their professors as having potential for careers as international soloists—engaged in periods of intensely effortful practice at roughly the same time each day (Ericsson, Krampe, & Tesch-Romer, 1993). In contrast, violin students rated by researchers as likely to become music teachers did not have distinct deliberate practice routines.

Might Beneficial Habits Mediate the Relationship between Self-Control and Positive Life Outcomes?

The majority of human behavior is energized and guided by goals (Kruglanski, 1996), yet goal pursuit is not always easy or straightforward. Insofar as self-control predicts goal adherence and positive life outcomes, we propose that it may do so--at least in part--through beneficial habits. Although it may run counter to conventional views, it makes sense to think that individuals with better self-control would rely on habits to fulfill long-term goals. Consider, for example, eating oatmeal. The most important benefits of eating oatmeal—healthy body weight, lower cholesterol—are deferred in time. A person will also have to eat oatmeal on numerous occasions to experience its salutary effects. Yet eating oatmeal also carries immediate costs: It does not taste as good as a donut, a bagel with cream cheese, or a sugary cereal. Although eating oatmeal over the long-run is rewarding, eating oatmeal right now may not be. As such, each separate act of eating oatmeal may be vulnerable to psychological and situational forces that tilt behavior toward immediate gratification, including negative mood (Tice, Bratslavsky, & Baumeister, 2001) and the presence of temptation.

Habits and routines provide structure to daily life such that the desired behavior—eating oatmeal—will be reliably triggered in the appropriate circumstances, even when it might not be easy to deliberately enact it. Habits thus offer a potentially powerful strategy that we argue individuals with better self-control use to safeguard their long-term goals from being derailed. Relying on habits should also have important downstream consequences. In the immediate term, it might mean that goal-relevant behaviors can be initiated automatically and effortlessly. If true, the relationship to habits may help explain the surprising observation that self-control is associated with less effortful inhibition in daily life. In the medium-term, it might mean making steady progress toward important goals. And the cumulative effect of beneficial habits, over long periods of time, should be evident in goal attainment.

Support for our theoretical assumptions thus crucially depends on demonstrating evidence for an association between self-control and beneficial habits. We are aware of one study that found an association between self-control and bad habits. In this recent study (Adriaanse, Kroese, Gillebaart, & de Ridder, 2014), 77 female undergraduates completed self-report measures of self-control and of the habit for eating unhealthy snacks. Participants then completed a food diary for seven days in which they logged daily intake of unhealthy snacks. Better self-control predicted weaker unhealthy snacking habits, which in turn predicted lower daily consumption of unhealthy snacks. No association was found between self-control and the habit for eating fruit or daily fruit consumption. According to the authors, fruit consumption (which is rated as both healthy and tasty) does not represent a typical self-control problem.

In the current investigation, we sought to extend this prior study by focusing on adaptive behaviors that are known to rely on self-control and that are conducive to habit formation. We chose beneficial habits because self-control is associated with positive outcomes as much as it is with the avoidance of negative outcomes (de Ridder, et al., 2012). In this way, we examined the strategies that individuals with better self-control use to facilitate attainment of desired ends rather than what they avoid doing to prevent bad outcomes.

Overview of the Current Investigation

The primary objective of this investigation was to test whether self-control is in fact related to beneficial habits. We tested this hypothesis in six studies involving over 2,200 participants, and spanning adolescents to middle-age adults. Based on the above considerations, we predicted that self-control would be reliably associated with beneficial habits. In order to provide more generalized evidence for an association between self-control and beneficial habits, we sampled from a wide range of behaviors, including exercising, eating healthy food, and sleep (Study 1), studying and doing homework (Studies 2, 3, 4, and 6), and practicing mindfulness meditation (Study 5). To further support the aim of broader generalizability, we assessed self-control using multiple different self-report measures as well as direct behavioral assessments.

Complementary to the main objective, we also tested whether habits might explain the relationship between self-control and positive life outcomes, in the short-term, medium-term, and long-term. Studies 1 through 3 focused on the short-term outcomes of relying on beneficial habits, including reduced effortful inhibition and motivational interference, and greater resilience in difficult circumstances. In Study 1, we measured effortful inhibition using health-related behaviors that represent typical self-control dilemmas—in which a temptation or maladaptive impulse must be inhibited—including exercise, eating healthy food, and going to sleep and waking up on time. In Study 2, we measured motivation interference as the amount of intrusive thoughts, level of distractibility, and behavioral impairment following a work-leisure conflict. In Study 3, we measured resilience as the ability to study under difficult circumstances (e.g., when under stress, when in a bad mood).

Study 4 focused on medium-term outcomes of relying on beneficial habits, whereas Studies 5 and 6 focused on long-term outcomes. Study 4 was a study of high school seniors that examined teacher-reported classroom engagement and homework completion. Study 5 was a three-month prospective longitudinal study of teenage youth that examined accomplishing mindfulness meditation practice goals. Study 6 was a multi-year longitudinal study of high school seniors that incorporated measures of medium-term academic outcomes (turning in homework on time) and long-term academic outcomes: high school grades and college persistence.

Study 1: Short-Term Outcomes—Habits and Less Effortful Inhibition

Health behaviors, such as going for a run or eating a healthy breakfast, typify goal-relevant actions that must be repeated over time in order to be worthwhile. No one who goes for a run one time should realistically expect to relish the long-term health benefits of exercise. Given the need for repetition and effort across extended periods of time, many health goals should benefit from habits. However, for many people health goals also represent a chronic tug-of-war against the temptation to do something more immediately gratifying (Hall & Fong, 2007). Given the links to both habit and self-control, health-related behaviors provide a useful preliminary test of our theoretical assumptions.

In Study 1, a large sample of adults completed a one-time online survey during which they answered questions about self-control, habits for eating healthy snacks, exercising, and sleeping, as well as other questions regarding the amount of effortful inhibition needed to carry out each behavior and the perceived automaticity of exercising. We hypothesized that self-control would be associated with beneficial health habits, less effortful inhibition, and greater automaticity. Further, we hypothesized that health habits would mediate the association between self-control and both effortful inhibition and behavioral automaticity.

Results and Discussion

In sum, Study 1 generated two main findings. First, self-control was associated with stronger habits for numerous health behaviors. That is, individuals with better self-control reported exercising and eating healthy snacks more frequently and under stable circumstances. Moreover, individuals with better self-control had more stable bed time and wake time sleep routines: They tended to go to bed and wake up at similar times regardless of the day of the week. These results provide the first empirical evidence to date that individuals with better self-control do in fact rely on beneficial habits and routines. Second, beneficial habits mediated the effect of self-control on the amount of effortful inhibition needed to initiate each behavior and perceived behavioral automaticity. Self-control predicted stronger habits, which in turn predicted the ability to initiate valuable behaviors automatically and without needing to exert as much effort, without taking much time to decide whether or not to enact the behavior, and without the need to inhibit strong temptations.

Study 2: Short-Term Outcomes—Habits and Reduced Motivational Interference

In Study 1, we showed habits alleviated some of the burden of having to use effortful inhibition to enact important health behaviors. These findings are consistent with our theoretical assumptions that strong habits can be initiated automatically and without effort. Recall also that we suggested habits may function to reduce cognitive intrusions and justifications that would otherwise need to be inhibited to adhere to goals. Therefore, in Study 2, we extended findings from Study 1 by testing whether habits would reduce the amount of motivational interference resulting from a work-leisure conflict.

In Study 2, we focused on academics—a different area of life relevant to both habit and self-control. Studying and doing homework require prolonged repetition for maximal payoff: Successful students do not study just once they study over and over again. Yet choosing to study when faced with opportunities to do something more fun is a common predicament (Grund, Brassler, & Fries, 2014). And even if a student decides in favor of studying, the joys of the foregone activity may not be soon forgotten. The decision to not meet up with friends, for example, can linger in a student’s mind even while he or she tries to study (e.g., “Am I missing something fun?”, “Maybe I should meet up with them after all.”). Focusing on studying when simultaneously brooding over missed opportunities would be, at minimum, difficult; the quality of learning will be impaired and the student will likely not persist for very long on difficult material (Grund, et al., 2014).

We suggest that just as habits reduce the amount effortful inhibition needed to perform the behavior, so too should they diminish the motivational interference following a work-leisure conflict. Alternative activities may have less immediate influence over cognition, motivation, and behavior for individuals that use daily routines and habits to structure the completion of important academic activities. Insofar as students with superior self-control are more capable of adhering to academic goals during difficult situations, we argue that they do so—at least in part—through the use of strong study habits. We therefore hypothesized that habits would be associated with reduced motivational interference following study-leisure conflict, and further, that habits would mediate the association between self-control and motivational interference.

Results and Discussion 

Results of Study 2 showed that self-control again predicted stronger study habits—measured via perceptions of behavioral automaticity and the combination of frequency and context stability—which in turn predicted lower motivational interference during study-leisure conflict. Consistent with hypotheses, results suggest that strong study habits alleviate cognitive, motivational, and behavioral impairments resulting from the decision to study despite opportunities for leisure.

Study 3: Short-Term Outcomes—Studying During Challenging Circumstances

In Study 3, we extended prior findings by testing the hypothesis that study habits would facilitate positive outcomes even under difficult circumstances. In exchange for course credit, a sample of university undergraduates completed a one-time online survey during which they answered questions about their self-control and their habit for studying, as well as additional questions about studying under conditions that are well known to require self-control (i.e., when tempted to do something other than study, when stressed, when in a negative mood, and when feeling strong aversion toward the task). Similar to Studies 1 and 2, we predicted that self-control would be associated with beneficial study habits, and further, that stronger study habits would mediate the association between self-control and studying during challenging circumstances.

Results and Discussion 

Results of Study 3 indicated that self-control predicted stronger study habits, which, in turn predicted studying even when stressed, when tempted to do something other than study, when experiencing strong aversion, and when in a bad mood. Because strong habits are triggered automatically by recurring situational cues, they may help protect valued goals from being usurped by fleeting moods and fluctuations in motivation. However, Studies 1 through 3 only established that self-control and beneficial habits are in fact correlated, and that habits have important short-term consequences. In the remaining studies, we turned our attention to the question of whether beneficial habits facilitate medium-term and long-term outcomes.

Study 4: Medium-Term Outcomes—Classroom Engagement and Homework Completion

In Study 4, we extended the findings reported thus far using a larger sample of high school seniors from a racially and socioeconomically diverse high school. Although Studies 1 through 3 offered initial evidence for our hypothesis that strong study habits would mediate the association between self-control and positive outcomes, it is possible that shared method variance between measures of self-control, study habits, and outcomes may have confounded observed associations. In Study 4 we addressed this limitation by using a novel behavioral measure to assess self-control and by using teacher-reported ratings of classroom engagement and quality of completed homework to assess positive outcomes. We also included a measure of intelligence (matrix reasoning) to rule out the possibility that individual differences in intelligence explained the associations between self-control, habit, and outcomes. Our main hypothesis, however, remained unchanged: We predicted thathomework habits would mediate the association between self-control and classroom engagement. 

Results and Discussion: 

Across Studies 3 and 4, self-control—assessed by multiple self-report questionnaires and a novel behavioral measure—reliably correlated with stronger study and homework habits. Moreover, strong habits predicted important academic behaviors, such as studying even when faced with conditions that normally require self-control and in terms of turning in homework on time and engaging during classroom learning activities. In Study 4, we relied on teacher-reported assessments of classroom engagement, alleviating concerns about shared method variance. Also of interest, in Study 4 students with better ability to regulate emotions and interpersonal behavior (e.g., allowing others to speak without interruption) also relied on strong homework habits to advance academic goals. Together, these results demonstrate that self-control predicts positive outcomes, in part, through its association with effective study and homework habits.

Study 5: Long-Term Outcomes—Accomplishing Meditation Practice Goals

While Studies 1 through 4 provided evidence for an association between self-control and beneficial habits, a possible criticism is that the evidence marshaled in these studies came from cross-sectional studies. It remains unclear whether self-control predicts habit strength at a later point in time, which in turn promotes long-term positive outcomes. Hence, the main goal of Study 5 was to address the predictive validity of self-control on habits using data from a prospective longitudinal study. In this study, we tracked a sample of teenage youth for three months and examined the development of mindfulness meditation practice habits. Specifically, we measured self-control before the start of an intensive five-day meditation retreat, and three months after the retreat we measured meditation practice habit strength.

Mindfulness meditation practice has been studied with regard to its beneficial effects on self-control (e.g., Papies, Barsalou, & Custers, 2011). However, the actual practice of meditation itself can require self-control: Meditation can feel tedious and uninteresting, and for novice practitioners inexperienced in attending to their inner experience, meditation may initially increase feelings of distress. Indeed, Bhante Henepola Gunaratana (1990) begins his classic meditation manual, Mindfulness in Plain English, somberly: “Meditation is not easy. It takes time and it takes energy. It also takes grit, determination, and discipline. It requires a host of personal qualities that we normally regard as unpleasant and like to avoid whenever possible” (p. 1). Given competing time demands and more desirable alternative activities in the course of everyday life, we suggest that adolescents with better self-control will be more likely to continue practicing meditation after the structure and support of the meditation retreat has longed since passed.

As in Studies 1 through 4, we hypothesized that self-control would prospectively predict stronger meditation habits three months after the retreat, and that these habits would in turn mediate the association between self-control and positive outcomes. In Study 5, we again measured habit strength using the product of behavioral frequency and context stability as well as perceived behavioral automaticity to rule out the possibility that method effects in our habit strength measure may have explained prior results. As our outcome measure we relied on adolescents’ self-assessments of the degree to which they had satisfactorily met their meditation practice goals.

Results and Discussion 

Using a longitudinal design, Study 5 showed that better self-control prospectively predicted beneficial habits. Specifically, self-control, measured before the start of a five-day meditation retreat, predicted stronger meditation habits three months later. Importantly, these effects were consistent regardless of whether habits were measured as the product of behavioral frequency and context stability or as perceived behavioral automaticity. Furthermore, effects were independent of prior meditation experience and goal commitment. Extending the findings of Studies 3 and 4, we also provided evidence that strong habits mediated the association between self-control and successfully accomplishing long-term goals. Together, these findings indicate that adolescents with better self-control were better able to stick to their long-term meditation practice goals through beneficial habits.

Study 6: Long-Term Outcomes—Earning Higher Grades and Persisting in College

Across five studies we have demonstrated that self-control reliably correlates with beneficial habits, measured as stable behavioral routines enacted under similar circumstances and as behavioral automaticity. Moreover, we have provided evidence that beneficial habits mediate the association self-control and positive outcomes across multiple time frames. However, in Studies 1 through 5, our outcome measures were reliant upon self-report and informant-report questionnaires. Therefore, in Study 6, we used two objectively measured indicators of long-term outcomes: grades earned in high school and college persistence. In a large sample of high school seniors (N = 918) from three racially and socioeconomically diverse high schools, we administered measures assessing self-control, homework habits, and homework completion. Subsequently, from school records we collected senior year grade point averages (GPA), and from the National Student Clearinghouse we collected college enrollment data. Extending the path model examined previously, we predicted that self-control would influence long-term academic outcomes through a combination of homework habits and medium-term outcomes, measured as homework completion.

In a replication of results from Study 4, homework habits also mediated the effect of both interpersonal self-control and work self-control (in separate models) on homework completion, senior year GPA, and college persistence.

Results and Discussion 

Study 6 showed that better self-control predicted stronger homework habits, which in turn predicted completing homework on time, and ultimately, earning higher grades in high school and a persisting in college. This latter finding is particularly noteworthy when considering that students who remain continuously enrolled full-time during the first year of college have a much greater chance of earning a degree (Ryu, 2012). For example, African American students who earn at least 20 college credits during their first year of college (indicating a year of full-time enrollment) have a 61% chance of earning a bachelor’s degree within 5 years. Conversely, African American students who do not earn 20 college credits during their first year of college have only a 21% chance of earning a baccalaureate degree within 5 years. The effect of full-time enrollment versus non-full-time enrollment on later degree completion is equally striking for White (78% vs. 35%) and Hispanic (61% vs. 22%) students.

Importantly, these results were significant above and beyond the effect of the high school attended, demographic characteristics, and intelligence. Moreover, we used objectively measured academic outcomes, thereby minimizing the problem of shared method variance. The prospective longitudinal design of this study also gives us greater confidence that homework habits were responsible for the observed correlations with academic outcomes rather than the other way around. Extending the results of prior studies, we also showed that medium-term positive outcomes (homework completion) mediated the effect of homework habits on both GPA and college persistence. 

General Discussion

It has been commonly assumed that self-control enables positive outcomes through “in the moment” inhibition of temptation. While these descriptions are understandable given the connotations of closely associated terms such as willpower, the current research suggests that self-control is also reliably associated with beneficial habits, those automatic action dispositions forged by repeating a particular behavior in stable circumstances (Wood & Neal, 2007). Specifically, individual differences in self-control—measured using valid self-report questionnaires and behavioral measures—correlated with habits for exercising, eating healthy snacks, and sleeping (Study 1), as well as for studying and doing homework (Studies 2, 3, 4, and 6). Results of Study 5 also indicated that self-control prospectively predicted beneficial meditation habits—measured as the combination of behavioral frequency and context stability and as behavioral automaticity—three months after the end of a meditation retreat.

Implications for Self-Control Research

In addition to highlighting the association between self-control and beneficial habits, these findings extend research linking self-control to positive life outcomes in two important ways. First, no prior studies have shown why individuals with better self-control rely less on effortful inhibition to enact behaviors that track long-term goals. Results of Study 1 and 2 addressed this issue directly: Beneficial habits mediated the association between self-control and both effortful inhibition and motivational interference. Specifically, in Study 1, self-control predicted stronger habits, which in turn predicted the initiation of desirable health behaviors (for exercising, eating healthy snacks, and going to bed on time) automatically and with little need for effortful inhibition. In Study 2, self-control predicted stronger study habits, which in turn reduced the amount of intrusive thoughts, negative mood, and behavioral impairment following a work-leisure conflict. These data suggest that by relying on stable habits and routines, individuals with better self-control can enact important behaviors more automatically and effortlessly.

Second, the current research demonstrated that habits explain the relationship between self-control and numerous positive life outcomes. Specifically, beneficial habits mediated the effect of self-control on short-term outcomes, measured as the ability to study when stressed, in a bad mood, or tempted to do something else (Study 3), and medium-term outcomes, measured via teacher-reported classroom engagement (Study 4). Over extended periods of time, habits also mediated the effect of self-control on accomplishing meditation practice goals three months after a meditation retreat (Study 5), and earning higher grades in high school and persisting in college (Study 6). Beneficial habits, perhaps more so than individual acts of effortful inhibition, therefore represent an important though often neglected factor linking self-control to positive life outcomes.

Taken together, the current investigation offers some of the first empirical evidence outside of laboratory settings exploring the mechanisms underlying the association between self-control and positive life outcomes. In doing so, the current research adds to a growing literature calling for a broader conceptualization of self-control as more than just the effortful inhibition of impulses (de Ridder, et al., 2012; Fujita, 2011). It also integrates research on self-control with a well-established body of research examining the determinants of goal pursuit more generally (Gollwitzer, 1990; Mann, et al., 2013). Further, the variety of samples (adolescents, high school students, college students, and adults living in the United States), methods (cross-sectional and longitudinal studies) and procedures used (self-report and behavioral measures of self-control, multiple measures of habit), combined with the diversity of life domains assessed, provides more generalized evidence for a reliable association between self-control and beneficial habits.

Directions for Future Research

How is self-control related to beneficial habits? In Study 1 for example, we demonstrated that exercising frequently and in the same place and time predicted greater exercise automaticity. Yet this study did not examine how individuals with better self-control managed to exercise in a manner conducive to the development of automaticity. We suggest that for long-term goals, self-control can be strategically deployed to organize situations and remove temptations that obstruct continued repetition of goal-relevant behavior, and hence, the development of automaticity.

An important question for future research then is whether different self-control strategies are of equal value for developing beneficial habits (Duckworth, Gendler, & Gross, 2014). We doubt that this is the case. Habit development is facilitated to the degree that direct valuation of competing goals is minimized (Wood & Neal, 2007; Yin & Knowlton, 2006). That is, behaviors that require goals or intentions to be actively represented every time they are enacted will likely not become habits. For example, students who must decide each day anew whether to do homework while simultaneously tempted by the television will likely find that the decision to do homework becomes no easier over time. This view argues that self-control strategies that operate prior to encountering temptations may be more beneficial in creating habits compared to strategies that operate after encountering temptation. Proactive self-control strategies that preemptively remove competing alternative goals (Duckworth, et al., 2014; Gollwitzer, 1999; Gross, 1998) should reduce the need to reevaluate the desired behavior (e.g., do homework) in relation to an available alternative (e.g., watch television), which in turn may clear the way for repetition of the desired behavior, and hence, the development of automaticity. In contrast, reactive self-control strategies (including effortful inhibition) involve deliberate and direct comparisons of conflicting goals (“Should I do homework or watch television?”). Relying on effortful inhibition every time a desired behavior must be enacted could therefore stall the development of automaticity. Research comparing different self-control strategies would not only provide theoretical insights about how best to develop beneficial habits, but also practical benefits to individuals struggling to repeat valued behaviors.

Concluding Remark

In his meditation on habits, William James (1890) said 

“there is no more miserable human being than one in whom nothing is habitual but indecision, and for whom the lighting of every cigar, the drinking of every cup, the time of rising and going to bed every day, and the beginning of every bit of work, are subjects of express volitional deliberation. Full half the time of such a man goes to the deciding, or regretting, of matters which ought to be so ingrained in him as practically not to exist for his consciousness at all” (p. 122). 

Consistent with these observations, we demonstrated across six studies the salutary effects of beneficial habits for reducing effortful inhibition (Study 1) and motivational interference (Study 2), facilitating greater goal adherence (Studies 3, 4, 5, and 6), and promoting long-term outcomes (Study 6). We also showed that self-control—thought mainly to involve the effortful inhibition of single maladaptive impulses—enabled positive life outcomes through the deployment of beneficial habits. Collectively, these results offer a revised portrait of the self-controlled person as someone who relies upon beneficial habits to adhere to, and ultimately attain, enduringly valued goals.

Acknowledgments

We note here that we also tested an alternative mediation pathway--in which stronger habits predicted better self-control, and in turn better outcomes--in Studies 1, 2, 3, 4, and 6. In most cases, we found support for this alternative pathway. For clarity of exposition, we do not report the results of each alternate mediation analysis in the manuscript.

Potential Criticisms and Limitations
We see at least two potential criticisms of the current study. We offered theoretical reasons for why individuals with better self-control might rely on beneficial habits. However, it is also plausible that beneficial habits facilitate better self-control, which in turn predicts positive life outcomes. We tested this reverse pathway in each study (except for Study 5 because self-control was only measured before the meditation retreat). In most cases, we found support for this alternative hypothesis. On this very point, William James (1890) conjectured that habits may help shield our limited cognitive capacity from being unnecessarily squandered on trivial tasks. In a complementary way, habits may also help prevent mental fatigue that would otherwise impair self-control for when it is needed most, for example, during unpredictable encounters with strong temptation. This reverse pathway, from habits to self-control to positive outcomes, suggests interesting avenues for future research. For example, it may be the case that individuals who are thrown off their existing habits and routines due to a change in circumstances (e.g., travel to an unfamiliar place, moving to a new town, the birth of a baby) experience more self-control difficulties and greater difficulty sticking to their goals.
A second potential criticism of the present research is that habits might themselves be seen as a positive outcome. If so, it might make less sense to differentiate habits from the outcomes that they are expected to predict (at least as measured in the current research). Our decision to differentiate habit from positive outcomes is based on both theoretical grounds—in which habits are seen as distinct from and at the same time related to goal pursuit (Wood & Neal, 2007)—and prior empirical research (Adriaanse, et al., 2014). Nonetheless, we offer several empirical arguments against the possibility that habits were coextensive with our outcomes. The correlations between self-control, habit, and outcomes in each study hovered around r = .20 to .40. Although this is traditionally viewed as a moderate sized effect, correlations of this magnitude only account for 4% to 16% of the shared variance. Confirmatory factor analyses also revealed that treating self-control, habit, and outcomes as separate factors fit the data better than a single-factor solution, or any two-factor combination of the different constructs. Using data from Study 6, for example, a three-factor solution fit the data better than a two-factor solution in which indicators for homework habits and homework completion were loaded onto a single factor and indicators for self-control were loaded onto another factor (Δχ2(2)= −188.80, p < .001).
The criticism that habits and positive life outcomes are one in the same thing may derive in part from the inclusion of behavioral frequency in the assessment of habit strength (Ajzen, 2002). After all, frequently enacting an important behavior can be seen as an end in itself. This issue was partially addressed by using a measure of behavioral automaticity to assess habit strength (Studies 1, 2, and 5), as well as by measuring sleep habits independently of behavioral frequency. To further address this concern, however, we reanalyzed data from Study 6 to explore whether simply having a stable routine, but independent of the frequency of this routine, would predict positive outcomes. We used data from Study 6 in this exploratory analysis given the power to detect smaller effects. Specifically, we created a measure of homework habit strength by multiplying together the two ratings of context stability (time and place), but excluding ratings of behavioral frequency. We then reran our mediation model using this new habit measure. Results were unchanged. Self-control predicted more stable homework routines (doing homework in the same place at the same time) which in turn predicted greater homework completion and long-term academic outcomes (senior year GPA and full-time college enrollment). Results of this exploratory reanalysis further confirm that self-control does in fact predict reliable routines—even independently of their frequency—and that these routines in turn facilitate positive life outcomes.
Despite the consistency of our results across six studies, there are several limitations. First, although the prospective longitudinal design of Study 5 supports some inferences about the direction of effects, our studies were nonexperimental. Therefore, causal relations between self-control, habit, and positive life outcomes cannot be confirmed unequivocally. And although we quantified habit strength using the two most common measures in social psychology (as the product of frequency and context stability, and as perceived behavioral automaticity), we nevertheless relied on traditional retrospective self-report measures. Future studies might incorporate ecological momentary assessments of behavior (Lally, et al., 2010; Wood, et al., 2002) to examine the association between self-control and daily routines.