The economics of effort: why we don't like thinking hard

How recent research debunks the myth of mental depletion, and what teachers can do to make effort feel worth the price.

Ryan wasn’t stupid. He could dismantle a classmate’s argument in seconds and had a knack for saying exactly the wrong thing at precisely the funniest moment. But ask him to put pen to paper and he’d act like you’d suggested he take up needlepoint.

On one occasion, I sat next to him while he stared blankly at a question about dramatic irony in the opening of An Inspector Calls.

“Any reason you’ve written your name and then stopped?”

He shrugged. “Yeah. I always get it wrong, so what’s the point?”

He wasn’t being dramatic. He wasn’t even sulking. Just quietly resigned, like he was pointing out the expiry date on a yoghurt. To him, thinking hard seemed like a bad investment. Ryan, entirely rationally, had run the numbers in his head: high cost, low chance of reward, why bother?

What looks like laziness can sometimes be pessimism in disguise. The world - and the classroom - is full of Ryans. We’re all capable of thinking hard but we don’t always believe it’s worth the effort.

In recent years, cognitive psychology has quietly dismantled one of education’s most pervasive myths: that thinking is like a fuel tank. That attention, focus, and effort are finite resources, gradually depleted by hard work and magically replenished by sugar, water, or a quick stroll around the playground.

This idea, known as ego depletion, was once gospel. Like all seductive nonsense, it made perfect intuitive sense. People got tired when they thought hard, so we assumed they ran out of something. The problem is, the research didn’t hold up. Study after study has failed to replicate the idea that willpower is a limited substance we simply exhaust. Like phlogiston and learning styles, ego depletion has now been quietly ushered out of the psychological spotlight.¹

What’s taken its place is far more interesting and far more useful. The current front-runner in explaining why thinking feels effortful is the Expected Value of Control (EVC) theory.

EVC, developed by Shenhav, Botvinick, and Cohen (2013), proposes that we engage in mental effort based on a rational cost–benefit analysis. Rather than effort being a limited resouce, the brain decides whether to invest effort by weighing up three factors:

1. Reward – how valuable success would be

2. Efficacy – the likelihood that effort will lead to success

3. Cost – how mentally taxing the effort feels

If the expected value is high, we’re more likely to apply effort. If not, we disengage. The theory reframes effort not as something we run out of, but as something we choose to spend — or withhold — based on perceived return. This helps explain why we avoid hard tasks that feel pointless, and why we willingly tackle demanding ones when the stakes feel worthwhile.

The brain, far from being a simple reaction machine, acts more like a stingy accountant. It tots up the likely reward of succeeding at a task, assesses the probability of success if effort were applied, and compares that against the anticipated cost of trying. If the reward is high and the odds are decent, the effort feels worth it. If not, we mentally check out.

In this light, what we usually perceive as “low motivation” might really be rational disengagement. The problem isn’t laziness — it’s plausible economics: we calculate that the pain of thinking outweighs the gain of success. This turns the usual motivational logic on its head. We tend to assume that motivation drives success: if students just wanted it more, they’d do better. But the evidence suggests the opposite is more often true. Success breeds motivation.² When students experience real, meaningful progress — when effort actually pays off — their willingness to try increases. Success justifies effort.

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And this, of course, has consequences for the classroom.

When a student looks bored, gives up quickly, or flat-out refuses to start, the instinct is often behavioural: offer a reward, issue a sanction, raise an eyebrow. But if the Expected Value of Control theory is right, then the problem isn’t attitude — it’s arithmetic. If a student believes success is unlikely, or that the payoff won’t justify the mental effort, then no amount of cajoling will make them try. What matters is whether effort feels like a worthwhile gamble.

So what tips the scales?

Success has to feel possible. Not guaranteed — that cheapens it — but within reach. We all want students to be able to grapple with difficult ideas but this is only likely when built on a firm foundation of success. If the task is too hard, success vanishes; too easy, and it becomes meaningless. The sweet spot lies where challenge meets clarity: when the path is hard but visible. This means we’re constantly juggling the support and scaffolding we offer. If resources are easy to remove we can say to students, ‘I want you try without this today,’ or, ‘You can have this for 5 minutes then I’ll take it away,’ or, ‘You can have the support today but we’ll try without next lesson.’ The message should be, everyone can have the support they need to be successful for as long as they need but in order to be truly successful you need to do it without the support.

Outcomes must feel earned. Praise for participation or vague effort sends the message that success is arbitrary — and if it’s arbitrary, that the system - schools and teachers - can’t be trusted. Students need to see that what they do changes what they get. That means feedback must be specific, improvement must be visible, and success must be attached to deliberate, effortful thinking.

The cost of effort has to be tolerable. Confusion is expensive. Tasks that feel aimless, over-complicated, or conceptually vague drive up the cognitive transaction fee. This is why load-managing, fully guided instruction makes so much difference. What helps is not simplification, but structure: worked examples, models, and prompts that make the difficulty navigable. This isn’t about making work easier, it’s about making the path clearer.

In short, if we want students to try harder, we must stop treating motivation as a fixed trait and start treating it as a logical outcome. They’ll try when they believe trying works. Our job is to give them reasons to believe. This doesn’t mean students never get tired, of course they do. But it’s not just because they’ve “used up” their effort. It’s because their brains no longer believe the game is worth playing.

The job of teaching, then, is not simply to demand effort. It’s to make effort seem like a good investment. We do that not by lowering the bar, nor by artificially inflating the rewards, but by designing tasks that make success both desirable and achievable.

So next time a student stares blankly at the page, don’t say “try harder.” Ask yourself, what are they calculating right now? And how might I tip the balance?

1. The original ego depletion theory, popularised by Baumeister et al. (1998), claimed that self-control draws on a finite mental resource, like a fuel tank. Early studies suggested that exerting willpower on one task impaired performance on subsequent tasks. However, a major replication effort led by Hagger, M. S., Chatzisarantis, N. L., et al (2016) involving over 2,000 participants across 23 labs found no evidence for the effect. Meta-analyses have since confirmed that the phenomenon is either vanishingly small or dependent on questionable research practices. Lurquin & Miyake (2017) argue that the problems with ego depletion research go deeper than failed replications. They describe a conceptual crisis, pointing out that the theory itself is poorly defined, lacks precise mechanisms, and can’t consistently predict when depletion should or shouldn’t occur.

2. Research consistently shows that perceived competence - the belief that one can succeed - is a key driver of motivation. According to Self-Determination Theory (Deci & Ryan, 1985), one of the three basic psychological needs that fuel intrinsic motivation is a sense of competence. Similarly, Bandura’s (1997) work on self-efficacy shows that past success builds confidence and increases future effort. More recently, Hulleman et al. (2010) found that helping students see the relevance and attainability of success improved both motivation and performance.