Writing this day by day, rather than all at once, this series has taken a number of twists, turns, and quite frankly, unexpected detours, some of which may have made the underlying logic hard to follow. (Indeed, to the extent that these posts shed light on the inner workings of my mind, you can tell how frightfully coherent my day-to-day has become. Frightfully, being the operative word…)
In any case, in this, my last ‘science’ post on the subject, I want to revisit some of the topics we’ve discussed, and clarify and expand on others, so that you may leave this series having learnt something – either about me, or self-gratification, or cookies, at the very least.
What was it we learned, after all?
#1 Performance in the cookie task is not well explained by cognitive control.
The way that we classically conceive of self control – as an ability to control our impulses and urges – is probably not the primary thing that's being measured in the cookie task, since delay-times only correlate weakly with measures of cognitive control.
#2 On the other hand, performance in the task may be explained by verbal ability.
Verbal ability is a strong predictor of individual performance in the task. This raises the possibility that linguistic competence guides how well children are able to conceptualize and formulate distraction strategies, and thus determines how long they are able to delay. If this interpretation is right, it would indicate that delay-time in the task may be an indirect measure of verbal ability. This would have critical implications for how we interpret the results of Mischel’s longitudinal studies.
#3 However, it’s possible that while performance in the task is highly correlated with verbal ability, it is not caused by it.
The link between verbal ability and ability to delay isn’t necessarily causal. It could also be that the two abilities arise from a similar source – such as the home environment, or an innate set of traits that tend to occur in tandem. For example, having blond hair does not cause me to have blue eyes, but the two traits are linked genetically, and frequently appear in the same individual, as they do in me.
#4 That said, there are good reasons to believe that verbal ability can account for performance differences in the task.
For one, there are a host of experiments in the “delay of gratification” paradigm that have found that teaching children conceptual strategies for delaying makes them significantly better at delaying. This suggests that learning and strategy do play a vital role in children’s “ability to delay.”
#5 Why give less credence to the other possibilities?
With regards to genetics: Except in the case of severe learning disorders, early environment has been shown to be a far more powerful determinant of language development than an individual’s genetics. Given that, it seems highly unlikely that verbal ability and ability to delay would be tightly coupled simply on the basis of genetics. While genetics undoubtedly has some part to play, it seems to add little explanatory value here.
With regards to environment: We know that vocabulary acquisition is a function of environment, and that children from poorer families tend to have worse vocabulary scores and shorter delay times. On this basis, it is tempting to conclude that lower-income parents are simply poor models of language and “delay of gratification” alike. This prospect would be impossible to rule out without further study. However, I think that there is reason to believe that class stereotypes about self control are both misconstrued, and also very likely irrelevant to behavior in the cookie task.
Further, and more critically, I think this is fundamentally the wrong way to look at the issue. How people behave, in general, is intimately tied up with the culture they are a part of and the values they adhere to, which is in turn, tied to the language they speak. In other words, even when we want to separate things out, and look to “environment” to explain something, we never get very far afield from language.
#6 What to make of all this?
When we speak of “self control” colloquially, it is important to understand that we are using an umbrella term that points to a range of behaviors, with various and sundry determinants. Depending on the situation, those determinants may be cognitive, and may relate to the function of our prefrontal cortex and the wider workings of our mid-brain dopamine system; they may be linguistic, and may depend on the verbal and conceptual strategies we employ to stay our impulses; they may be cultural, and may be explained by our values and the situational and societal constraints we find ourselves working with; and that is just to name a few.
In all this, I think it is essential that we pinpoint what the causal mechanism is that best explains the behavior. For example, if we think of someone coming to the doctor complaining of an ache in our side, it may be that they’ve partaken unwisely, and should be sent home with some anti-acids and a food advisory. Or it may be that they have appendicitis, and need to be operated on right away. Though the symptoms might present similarly at first, it would be critical as a doctor to look for the underlying cause, and not simply diagnose by the first label given. In the same way, it is not entirely clear that the behavior that produces successful cookie-delayers is the same behavior that helps a kid make the grades to get into college, or resist drug use, or wait to have sex – even though we may call all these behaviors “self control.”
In the literature on self control, there is still much to be done to illuminate the underlying mechanisms that vie to produce “self control.” In the meantime, I think it is helpful to look for useful correlates – like ‘cognitive control’ or vocabulary – that are empirically measurable, and point to mechanisms that are already fairly well understood. In a similar vein, we might begin to assess how ‘self control’ behaviors relate to culture by plumbing people’s backgrounds, the idiosyncracies of their language use, and the kinds of attitudes they express; or similarly, look to how they relate to personality, by administering well-established personality measures. It also seems vital that we assess behavior in tandem with these correlates, and not many years later, when the connection is invariably less clear.
These are what I would take to be important future avenues of research. As for what we understand now : it seems very likely that the cookie task is, in its way, an indirect measure of language ability. This would suggest that many of the ‘life outcomes’ that are predicted by the cookie task are related to verbal ability. Given the relation between socioeconomic status and verbal attainment in this country, this link is not altogether surprising. However, it points to just how important early-intervention and pre-K programs are, which can lay the foundation when it matters. While the efficacy of such programs varies widely, and more research needs to be done on how to achieve the most effective interventions, it is clear that they can make a substantial difference (see e.g., Give Well’s report on the nation’s preschool programs for at-risk children).
#7 I’m not in research, or in a position to affect policy. Is there anything I can do?
If you want to make a difference now, Give Well’s top charity recommendation in the states is the Nurse-Family partnership, which provides prenatal (and postnatal) support and training to young, low-income mothers, and which makes a significant difference in cognitive and social development.
# 8 ...
Which means we have learned, dear readers, that even the snarkiest of writers can polish off her posts with a tug at the heart strings, some money-grubbing organizations, and a sense of having, once again, taken the moral high road. If what you expected was panache, best wait for tomorrow.