In “Willpower with and without effort,” Ainslie characterizes the mechanisms underlying willpower (as distinct from mere habit) as being suppression and resolve. He consigns the hot/cool framework of willpower and of memory (Metcalfe & Jacobs, Reference Metcalfe and Jacobs1996, Reference Metcalfe and Jacobs1998, Reference Metcalfe, Jacobs and Tulving2000; Metcalfe & Mischel, Reference Metcalfe and Mischel1999) to a class of “visceral” theories of willpower that pertain only to reward perception and its suppression. Although not denying that the hot–cool balance can affect reward characterization and suppression, we argue, here, that it also makes important predictions concerning the other component, namely, resolve.

Explicit or episodic memory depends on the cool system. As detailed below, this system is responsible for mental projection into one's future, as well as for remembering one's past. Thinking about the future is necessary for an individual to “recursively self-predict” – the cognitive process that Ainslie argues is at the core of resolve. It follows that if cool system functioning were selectively impaired by stress (or for other reasons), an individual's ability to engage in recursive self-prediction, and with it their resolve, would also be impaired, with adverse results for willpower.

Resolve, within the Ainslian framework, involves perceiving a particular instance or violation as being a test-case of a larger category. Smoking a single cigarette is more than an inconsequential isolated act; it is seen as typifying an undesirable although specific behavior that jeopardizes one's future health. One resolves to do something, such as resist cigarettes, to benefit one's future self (who is imagined, in this case, to be healthy). Although not explicit in Ainslie's framework, his notion of recursive self-prediction implies the construct of a future self. The proposal that people use an internally generated image of their future selves to activate present behavior has a distinguished history in psychology going back to the study of Markus and Nurius (Reference Markus and Nurius1986) and elaborated extensively by others (e.g., Hershfield, Reference Hershfield2019; Oettingen & Mayer, Reference Oettingen and Mayer2002; Oettingen, Sevincer, & Gollwitzer, Reference Oettingen, Sevincer and Gollwitzer2018; Urminsky, Reference Urminsky2017). Many studies show that the mental recruitment of future selves predicts effective self-regulation (Frazier & Hooker, Reference Frazier, Hooker, Dunkel and Kerpelman2006; Frazier, Schwartz, & Metcalfe, Reference Frazier, Schwartz and Metcalfe2021; Hooker, Reference Hooker1992; Leondari, Syngollitou, & Kiosseoglou, Reference Leondari, Syngollitou and Kiosseoglou1998; Oyserman, Destin, & Novin, Reference Oyserman, Destin and Novin2015; Oyserman & Markus, Reference Oyserman and Markus1990). These “future selves” are characterized as mental representations of who we are – our own identities – projected into the future. They are an embodiment, on the positive side, of the person we aspire to become (Higgins, Roney, Crowe, & Hymes, Reference Higgins, Roney, Crowe and Hymes1994; Stokes, Reference Stokes, Strohschen and Lewis2019). On the negative side, they comprise a graphic portrayal of the alternative dismal fate to which we might succumb. Accessing such future selves readily is necessary for resolve-based willpower, which Ainslie argues is underpinned by ongoing monitoring of progress toward this goal. We evaluate if smoking the cigarette represents behavior that gets us closer to the healthy future self or to the dismal fate, and make a decision to act accordingly.

Many take temporal discounting – an adult variant of Mischel's (Reference Mischel2014) “delay of gratification” paradigm – to be the prototype paradigm of willpower. The role of the future self in this paradigm is obvious. In the temporal discounting paradigm, an individual is asked to abjure immediate but small rewards for the present self in favor of larger rewards for an imagined future self. If the individual cannot conjure up a future self then presumably those hypothetical future rewards are meaningless. There is no reason to resist immediate impulse. Willpower and the resolve that underpins it collapse. The extent to which the individual clearly imagines and identifies with the future self, then, appears to be crucial for the value accorded to those future rewards. Within the hot/cool framework, stress disrupts the ability to imagine a future self.

In the hot/cool framework, explicit or episodic memory is a cool system function, whereas conditioning and taxonomic and implicit learning are hot system functions. There is considerable evidence, from the amnesia literature, that cool explicit memory is dissociable from hot forms of memory. This selective cool-system-related explicit memory impairment seems, at first blush, to be unrelated to future thought or to willpower. Studies of amnesics, however, show that the explicit memory system and people's ability to think about the future are deeply linked (Tulving, Reference Tulving1985, Reference Tulving, Stuss and Knight2002). For instance, psychologists have studied amnesic patients, such as KC, who was purportedly unable to recall any particular instances of events from his life. Interestingly, KC, and other such amnesics, also experience enormous difficulty in thinking about the future (e.g., Schacter et al., Reference Schacter, Addis, Hassabis, Martin, Spreng and Szpunar2012). Furthermore, there is considerable evidence from neuroimaging that the same neural systems underlie both remembering events from one's own past and generating projections of oneself in the future (Okuda et al., Reference Okuda, Fujii, Ohtake, Tsukiura, Tanji, Suzuki and Yamadori2003). Mental self-time travel pertains to both past and the future.

There is also growing evidence that stress, especially at high levels, selectively impairs the cool system, while possibly even enhancing function of the hot system (Jacobs, Brown, & Nadel, Reference Jacobs, Brown, Nadel and Byrne2017). For example, Eich and Metcalfe (Reference Eich and Metcalfe2009), tested marathon runners who had just completed a 26.2 mile race (as compared to unstressed marathoners tested days earlier). They found selective stress-related impairment of explicit memory. Similarly, when New York City firefighters were tested for their memory of events experienced in dangerous fires, Metcalfe, Brezler, McNamara, Maletta, and Vuorre (Reference Metcalfe, Brezler, McNamara, Maletta and Vuorre2019) found that the degree of explicit memory impairment depended on the stressfulness of the fire. The “cool” system, then, is impaired under stress.

The hot/cool framework indicates that when stress selectively impairs the cool system it is not only explicit memory that is impaired, but also future projection. When people are experiencing high levels of stress, they are less able to contemplate their own future selves. As a result, their resolve, mediated by Ainslie's recursive self-prediction mechanism, dissolves. Stress-related dysfunction of the cool system, then, directly affects resolve-mediated willpower. The vulnerability of resolve to factors that negatively affects the cool system provides a testable explanation for why people under extreme stress exhibit two otherwise seemingly unrelated symptoms: impaired episodic memory and impaired willpower.