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Maybe it has nothing to do with self-control

A Scientific American article talks about a finding that refines a widely-reported association between self-regulation and academic achievement. This association relates to the famous ‘marshmallow test’, in which young children were left alone with a marshmallow, having been told that if they could hold off eating it until the researcher returns, they would get two marshmallows. The ability of the young pre-school children to wait has been linked to subsequent achievement at school, and indeed has been said to be as important as IQ.

The finding relates to other factors that might be involved in a child’s decision not to wait — specifically, children who live in an environment where anything they had could be taken away at any time, make a completely rational choice by not waiting.

Another recent study makes a wider point: the children in the classical paradigm don’t know how long they will have to wait. This, the researchers say, changes everything.

A survey of adults asked to imagine themselves in a variety of scenarios, in which they were told the amount of time they had been at an activity such as watching a movie, practicing the piano, or trying to lose weight, were asked how long they thought it would be until they reached their goal or the end. There were marked differences in responses depending on whether the scenario had a relatively well-defined length or was more ambiguous.

Now, this in itself is no surprise. What is a surprise is that, rather than the usual feeling that the longer you’ve waited the closer you are to the end, when you don’t know anything about when the outcome will occur, the reverse occurs: the longer you wait the more you think you’re getting farther and farther away from that outcome.

The researchers suggest that this changes the interpretation of the marshmallow test — not in terms of predicting ability to delay gratification, but in terms of the mechanism behind it. Rather than reflecting two opposing systems fighting it out (your passionate id at war with your calculating super-ego), waiting for a while then giving in may be perfectly rational behavior. It may not be about ‘running out’ of will-power at all.

According to this model, which fits the observed behavior, and which I have to say makes perfect sense to me, there are three factors that influence persistence:

  • beliefs about time — which in this context has to do with how the predicted delay changes over time, i.e., do you believe that the remaining length of time is likely to be the same, shorter, or longer;
  • perceived reward magnitude — how much more valuable the delayed reward is to you than the immediate reward;
  • temporal discount rate — how much shorter time is valued.

A crucial point about temporal beliefs is that they can change as time passes. So, if you’re waiting for a bus, then the reasonable thing to believe is that, the longer you wait, the less time you will have left to wait. But what about if you’re waiting at a stop very late at night? In that case, the longer you wait, the more certain you might become that a bus will not in fact be coming for many hours. How about when you text someone? You probably start off expecting a reply right away, but the longer you wait the longer you expect to wait (if they’re not answering right away, it might be hours; they might not even see your text at all).

Another important aspect of these factors is that they are subjective (especially the last two), and will vary with an individual. This places ‘failures’ on differences in an individual’s temporal discount rate and perceived reward magnitude, rather than on poor self-control.

But what about the evidence that performance on this test correlates with later academic achievement? Well, temporal discount rate also appears to show ‘trait-like stability over time’, and has also been found to correlate with cognitive ability. Temporal discount rate, it seems to me, has a clear connection to motivation, and I have talked before about the way motivation can make a significant impact to someone’s IQ score or exam performance.

So maybe we should move away from worries about ‘self-control’, and start thinking about why some people put a higher value on short waiting times than others — how much of this is due to early experiences? what can we do about it?

We also need to think very hard about the common belief that persistence is always a virtue. If you’re waiting for a bus that hasn’t come after an hour, and it’s now one in the morning, your best choice is probably to give up and find some other means home.

Although persistence is often regarded as a virtue, misguided persistence can waste time and resources and can therefore defeat one's chances of success at superordinate goals . . . Rather than assuming that persistence is generally adaptive, the issue should be conceptualized as making judgments about when persistence will be effective and when it will be useless or even self-defeating. (Baumeister & Scher, 1988, pp. 12–13)

All of which is to say that, as with all human behavior, persistence (sometimes equated to ‘will-power’; sometimes to 'self-regulation') is a product of both the individual and the environment. If some children are doing well and others are not, perhaps you shouldn’t be attributing this to stable traits of the children, but to the way different children perceive the situation.

Nor is it only in the academic environment that these things matter. Our ability to delay gratification and our motivation are attributes that underlie our behavior and our success across our lives. If we turn these ‘attributes’ around and, instead of seeing them as personal traits, rather see them as dynamic attributes that reflect situational factors that interact with personal attributes, then we have a better chance of getting the results we want. If we can pinpoint perceived reward and temporal discount rate as critical factors in this individual — environment interaction, we know exactly what variables to consider and manipulate.

We are built to like simple solutions — a number, a label that we can pin on ourselves or another — but surely we have become sufficiently sophisticated that we can now handle more complex information? We need to move from considering people, whether ourselves or others, as independent agents acting in a vacuum, to considering them as part of an indissoluble organism — environment interacting unit. Let’s get away from a fixation on IQ scores, or SAT scores, or even complex multi-factorial scores, and realize those, even the most predictive ones, are only ever one part of the story. No one is the same person at every moment, and it’s time we took that point more seriously.


McGuire, J. T., & Kable, J. W. (2013). Rational Temporal Predictions Can Underlie Apparent Failures to Delay Gratification. Psychological Review, 120(2), 395–410. doi:10.1037/a0031910

Baumeister, R. F., & Scher, S. J. (1988). Self-defeating behavior patterns among normal individuals: Review and analysis of common self-destructive tendencies. Psychological Bulletin, 104, 3–22. doi:10.1037/ 0033-2909.104.1.3