Several studies have found humility to be linked to greater self-control. A neurological study conducted to investigate the structural neural basis of trait modesty has found an indirect association with self-control (Zheng, Wu, Jin, & Wu, 2017). Although modesty is often considered as a behavioural self-presentation (Cialdini et al., 1989; Tice et al., 1995; Wosinska et al., 1996), Zheng and his colleagues (2017) conceptualised trait modesty as a personality disposition that consists of a cognitive evaluation process, an accurate view of the self, and a tendency to show care and concern for others. Therefore, trait modesty in this study could arguably be said to be measuring the same construct as humility. The study found that people with higher trait modesty was associated with greater regional gray matter volume in the dorsolateral prefrontal cortex. The dorsolateral prefrontal cortex has been shown to be essential for successful emotional and behavioural self-regulations (Banfield et al., 2004). Greater activation of this region was strongly correlated with successful self-control and was found to help regulate one’s behaviours so as to adapt to social norms (Hare, Camerer, & Rangel, 2009; Barbey et al., 2009, Spitzer et al., 2007). Therefore, Zheng and his colleagues (2017) suggest that many of the positive outcomes of trait modesty could be due to greater self-control.
Experimental studies have provided more direct association between humility and self-control (Tong, Tan, Chor, Koh, Lee, & Tan, 2016). The studies found that people made to feel humble sustained longer in a handgrip task, controlled their appetite better, and persevered on when faced with a frustrating task. Many of the humility-related outcomes seem to require effective self-regulation. For example, the prosocial outcomes related with humility may require one to inhibit his or her egoistic tendencies in order to exhibit pro-social behaviours such as gratitude (Exline & Hill, 2012). Therefore, similar to Zheng and his colleagues (2017) suggestion, Tong and colleagues (2016) also proposed that greater self-control could be a mechanism behind the outcomes associated with humility.
Ego Depletion and Self Control
The idea is that self-control taps into a pool of limited mental resources (Baumeister, Bratslavsky, Muraven, & Tice, 1998). When the mental resources are used up, self-control is often impaired, a state typically known as ego depletion. Experimental studies have shown that when participants were required to perform an unrelated ego-depleting task that required self-control, such as supressing their emotions, their performance on a subsequent self-control task was often hindered. For example, participants who had their ego depleted gave up faster on unsolvable puzzles (Baumeister et al., 1998), took more risks (Freeman & Muraven, 2010), and procrastinated more (Vohs et al., 2008).
The topic on ego depletion became a hot topic ever since Baumeister and colleagues (1998) demonstrated its effects. A meta-analysis conducted in 2010 demonstrated a medium-to-large effect size of ego depletion (Hagger, Wood, Stiff, & Chatzisaran, 2010). However, in recent times, the ego depletion effect was questioned and argued to be due to publication bias (Carter & McCullough, 2014). A subsequent meta-analysis conducted by the authors that accounted for publication bias found that the ego depletion effect was indistinguishable from zero (Carter, Kofler, Forster, & Mccullough, 2015).
Nevertheless, there are researchers that refuted the claims that the ego depletion effect is non-existent (Baumeister, Tice, & Vohs 2018). They argued that Carter and colleagues (2015) meta-analysis discarded many published literatures and used statistical techniques with debatable validity in order to achieve a zero ego depletion effect. Even Carter himself recently questioned the usage of the statistical techniques used in his meta-analysis (Carter, Schönbrodt, Gervais, & Hilgard, 2017). An updated meta-analysis conducted to look into Carter’s study found that some of the ego depleting tasks were indeed ineffective in inducing ego depletion (Dang, 2017). However, the study also found that attention essay, stroop task, and emotion videos were all considered to be reliable. Following that finding, Dang and colleagues (2017) pre-registered their study and conducted their own experiment using the stroop task to see if it was reliable in inducing ego depletion. The results found a significant effectiveness in the effect of ego depletion. Therefore, their results demonstrated that ego could indeed be depleted, as long as the initial task was deemed depleting enough.
