Sleepwalk bias and the role of impulses

The psychologist and science writer Stuart Ritchie reports on yet another famous psychology finding that hasn’t replicated. A 2011 study claimed that the verdicts of a group of Israeli judges varied wildly depending on the time of the day: they were far more likely to grant parole after lunch than before lunch, when they were hungry. This study has been much-discussed, in particular because it featured in Daniel Kahneman’s Thinking, Fast and Slow. Many have argued that we’re captives of our impulses and emotions to an extraordinary degree, giving this as an example.

Recently, another study tested the hypothesis that hunger makes judges harsher in a different context, looking at court decisions from India and Pakistan. If the hypothesis is true, then Muslim judges should be more likely to hand out convictions during Ramadan, when they are fasting. But in fact, the opposite was found: judges observing Ramadan were more likely to acquit the defendant. This is evidence the hypothesis may not hold up.

Daniel Lakens argued a few years back (i.e. prior to the publication of the new study) that the hypothesis is implausible on priors:

If hunger had an effect on our mental resources of this magnitude, our society would fall into minor chaos every day at 11:45. Or at the very least, our society would have organized itself around this incredibly strong effect of mental depletion.

There’s something to that, and it raises the question of why people find the study of the hungry Israeli judges intuitive.

***

In other contexts, I’ve discussed what I call sleepwalk bias. For instance, when people are predicting whether a disaster will happen, they often seem to neglect the fact that people will try to prevent it. Or at least, they don’t take it into account to the extent that it deserves. They effectively think that (in many cases) people will sleepwalk into disaster, to an extent that I believe is implausible.

Maurice-Merleau Ponty and, following him, Jon Elster, have discussed the same phenomenon in other contexts. Elster calls it “younger sibling syndrome”:

Our spontaneous tendency is to view other people as ‘‘younger siblings.’’ We do not easily impute to others the same capacity for deliberation and reflection that introspection tells us that we possess ourselves...The idea of viewing others as being just as strategic and calculating as we are ourselves does not seem to come naturally.

Something akin to sleepwalk bias or younger sibling syndrome may partially explain why many people find the Israeli judge study intuitive.* Most of us sometimes get “hangry” - we get irritable when we’re hungry. For the sake of the argument, let’s grant that the judges in the discussed studies did actually get hangry. Even if we grant that, it doesn’t necessarily follow that their decisions would be much harsher. Judicial decisions are highly consequential, and responsible adults don’t necessarily let their impulses translate into consequential decisions. Instead, they often restrain themselves, even if it’s 11:45 and they’d rather be off to lunch.

It is instructive to look at a group of people who don’t do that: young children. When young children get hungry, they often get extremely irritable - and in their case, it does tend to translate into actions. They often randomly and unfairly lash out at people, and may even hit them. Thus, people who believe that adult judges allow themselves to be strongly influenced by hunger are in effect thinking that they act like children. It’s similar to the younger sibling syndrome.

We are, of course, affected by hunger, fatigue, and other similar feelings and impulses. But we aren’t sleepwalking automata, blindly acting on our impulses. We are more deliberate and planned than a common but overly simplified view of human decision-making suggests. Impulses are very salient and striking, whereas the deliberate restraining of impulses is less salient. That may lead us to overrate the power of those impulses, and underrate people’s tendency to rein them in.

* No doubt there are also other factors, such as the fact that the finding is interesting and provocative. There’s also a risk of hindsight bias: I don’t remember having been sceptical of that study when I first read about it.