For decades, psychology and neuroscience have suggested that if humans and animals naturally try to make as little effort as possible, it is because putting in the effort is not enjoyable.

Another possible interpretation: is that it’s not the actual effort that individuals avoid, it’s the effort wasted – effort that leads you nowhere or whose benefits do not justify putting in the effort. This vision is explored in a recent article I co-wrote with Roy Baumeister at Harvard University, Guido Gendolla at the University of Geneva, and Michel Audiffren from the University of Poitiers and published in 2026 in Neuroscience & Biobehavioral Reviews.

Let me explain:

How did we come to pinpoint that it’s effort-wasting that people avoid rather than actual effort?

To support our thesis, we conducted a critical, two-pronged synthesis of the scientific literature. First looking at child development. We thought that, if the effort was intrinsically unpleasant, effort rejection should be observed very early in development.

Infants and young children do not show any spontaneous aversion to effort: they engage in it freely, associate pleasure with satisfaction, and only learn how to spare their efforts gradually. The example of 10-month-olds is particularly striking: after watching an adult persevere in a difficult task, they themselves redouble their efforts to solve a problem.

Later on, at around 6 years old, children smile more after achieving something difficult than when something is easy – as if the acutal resistance involved added value to their success. If effort were intrinsically aversive, none of this would be possible.

Secondly, we focused on studies of the “least effort principle” in animals and adults. The preference for the least costly path in terms of effort emerges only when the rewards are strictly equivalent – and disappears as soon as the benefits justify the investment.

Better still, several studies show that people prefer to actively engage in a task rather than remain passive, and that busy people are happier than idle people, even when they are forced to be active.

Why is this so important?

This shift in perspective is transforming our understanding of human motivation. It makes it possible to solve what some call the “paradox of effort”: if there is indeed a biological law of “least effort”, then how can we explain why millions of people voluntarily engage in demanding activities such as extreme sports, learning an instrument, lengthy studies – and find them enjoyable?

If effort is perceived as a neutral cost (i.e. neither positively nor negatively balanced), comparable to spending money, then it becomes logical that people agree to put in the effort when it pays off.

This approach reinstates human beings as agents capable of evaluating and making decisions, rather than as an organism perpetually battling against a biological repulsion to action. It also makes it possible to better distinguish between ordinary situations of disengagement – when faced with something deemed unfavourable – and pathological cases, where a real aversion to effort may arise.

In the second case, such resistance to effort is based on well-identified neurobiological mechanisms, notably a reduced activity of the dopaminergic system.

Dopamine plays a central role in motivation in this respect: it strengthens the sense of reward and stimulates the pursuit of goals. When dopamine is lacking, effort becomes truly unpleasant and the desire to engage withers away.

What should be the next steps for this research?

Several questions remain open.

It is still unclear in what conditions some people develop a real aversion to effort and which neurobiological mechanisms are involved. Dopamine function is often cited, but research has mainly focused on situations involving external rewards. However, few studies examine the intrinsic motivations behind actually seeking effort for the sake of it.

One practical question still stands: what if, rather than seeking to make tasks less burdensome in schools, at work, and in care sectors – we primarily sought to make them more justified and useful in the eyes of those who are required to do them? This could make all the difference.

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Nathalie André ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.