Want to Be Happier and Avoid Auto Accidents? A TED/BMJ Mashup

Are happy people responsible for fewer accidents? Should positive psychology be a mandatory module in high school Driver's Ed classes? Taken together, a new paper in the 2012 Christmas issue of BMJ and a recent TEDx talk tell a potentially interesting story about happiness, car crashes, and mind wandering. Let's see how this dangerous idea holds up to scrutiny.

Driving and Daydreaming

It seems rather obvious that distraction is not good for driving, regardless of whether the offending diversion is from external or internal sources. Daydreaming (now known as "mind wandering", its more formal and scientific-sounding name) is a very common state of mind while driving. We'll often travel 10 miles down the road without being aware of our surroundings at all. But does this make us more prone to accidents? Galera et al. (2012) asked this question in a study designed to determine who was responsible for a motor vehicle accident (a "responsibility case-control study"). In other words, was the driver in question responsible for the auto accident? And what were they doing at the time?

The authors interviewed 955 patients in the emergency room at Bordeaux University Hospital within 72 hours of a motor vehicle accident. They used a standardized instrument to determine if the patient was at fault (8-12 = responsible; 13-15 = contributory; >15 = not responsible). Notably, eyewitness reports were not considered. The interview protocol is described below (Galera et al., 2012):

During the interview, patients were asked to describe their thought content just before the crash. ... Each thought was classified in one of the following categories: thought unrelated to the driving task or to the immediate sensory input, thought related to the driving task, no thought or no memory of any thought. To capture the intensity of the thought when the mind was wandering, the participant filled in a Likert-type scale (0-10) for each thought, answering the question: “How much did the thought disrupt/distract you?” 

Scores were then categorized into three levels of mind wandering:

• mind wandering with highly disrupting/distracting content (unrelated to the driving task or to the immediate sensory input)
• mind wandering with little disrupting/distracting content (unrelated to the driving task or to the immediate sensory input)
• none reported (no thought or no memory of any thought or thoughts related to the driving task)

Also considered were possible confounding variables such as age, sex, season, time of day, vehicle model, amount of sleep (less than 6 hrs was considered sleep deprived), and use of any psychotropic drug in the previous week (sleeping pills, anti-seizure medications, and drugs for various psychiatric disorders).  Blood alcohol level was obtained from the medical record. Sources of external distraction were assessed (e.g., use of a mobile phone, texting, grooming, eating, watching TV, etc.), as was mood or emotional valence at the time of the crash (pleasure-displeasure on a 9-point Likert scale).

The major finding was that mind wandering with highly distracting content was associated with a significantly higher likelihood of crash responsibility than if the driver reported no mind wandering. Also significantly related to responsibility were the expected factors of alcohol use and sleep deprivation, as well as the "emerging risk factors" of external distraction [which seemed expected to me], negative affect, and psychotropic medication use (see figure below - click for a larger view).

Fig. 1 (Galera et al., 2012). Odds ratios for responsibility for road traffic crashes, adjusted for age, sex, season, time of the day, and location.


Thus, internally distracting thoughts were clearly associated with a greater risk of causing an auto accident, with a higher odds ratio than for external distraction and even alcohol use. But what are we to make of the association with negative affect (a "displeased" mood)? Do happy drivers make better drivers??

"A Wandering Mind Is an Unhappy Mind."

Matt Killingsworth gave a talk at TEDxCambridge (MA) about mind wandering and happiness, based on results obtained from an experience sampling study in thousands of people. An iPhone app and a web-based reporting system (trackyourhappiness.org) were used to record the data, and the findings were published as a short report in Science (Killingsworth & Gilbert, 2010).¹

Participants were randomly cued by the app to answer questions about their current state of happiness (“How are you feeling right now?” rate from 0-100), their current activities (“What are you doing right now?” report one or more of 22 activities), and whether they were mind wandering (“Are you thinking about something other than what you’re currently doing?” one of four options: no; yes, something pleasant; yes, something neutral; or yes, something unpleasant).




Want to be happier? Stay in the moment (Filmed at TEDxCambridge.)

Results suggested that the participants were less happy when they were mind wandering, and this difference was significant for neutral topics and (not surprisingly) for unpleasant topics.²

Crucially, the authors postulated that mind wandering caused unhappiness, even though the data were correlational in nature.³ In fact, other studies have shown the opposite: that negative affect can lead to mind wandering (Smallwood et al., 2009, 2011). This would make sense, for example, in cases of depression (rumination) and anxiety (excessive worry).

Mindfulness Training for Happy, Safer Drivers?

Or should it be the Driver's Ed module on positive psychology? OK, I'm being a little ridiculous here, although this might make a good topic for an Onion talk. Correlation does not equal causation, and we don't know whether the emotional valence of "displeasure" in the Galera et al., 2012 driving study was anger or unhappiness (or disappointment, embarrassment, fear, etc. for that matter). What we do know is that self-reported internal distraction, rated retrospectively after an accident, was higher when the driver was responsible for the accident than when they were not at fault. Now all we need is a trackyourhappiness study for drivers to get accurate, moment-by-moment experience sampling. Oh, wait...


Footnotes

¹ Although this was not mentioned in the talk... Perhaps it had something to do with the large discrepancies between some of the variables that were stated in the talk vs. published in the journal article (e.g., the frequency of sampling was "over the course of a day, minute to minute in some cases" in TEDx vs. a minimum of once a day and default of 3 times a day in Science, Supporting Online Material):

Next, participants were asked to indicate the times at which they typically woke up and went to sleep, and how many times during the day they wished to receive a sample request (default = 3, minimum = 1).

² Participants were mind wandering 46.9% of the time: pleasant topics in 42.5% of samples, unpleasant topics in 26.5% of samples, and neutral topics in 31% of samples.

³ In the Science paper, they explained it thusly: "time-lag analyses strongly suggested that mind wandering in our sample was generally the cause, and not merely the consequence, of unhappiness."


References

Galera, C., Orriols, L., M'Bailara, K., Laborey, M., Contrand, B., Ribereau-Gayon, R., Masson, F., Bakiri, S., Gabaude, C., Fort, A., Maury, B., Lemercier, C., Cours, M., Bouvard, M., & Lagarde, E. (2012). Mind wandering and driving: responsibility case-control study. BMJ, 345 (dec13 8) DOI: 10.1136/bmj.e8105

Killingsworth, M., Gilbert, D. (2010). A Wandering Mind Is an Unhappy Mind. Science, 330 (6006), 932-932. DOI: 10.1126/science.1192439

Smallwood J, Fitzgerald A, Miles LK, Phillips LH. (2009). Shifting moods, wandering minds: negative moods lead the mind to wander. Emotion 9:271-6.

Smallwood J, O'Connor RC. (2011). Imprisoned by the past: unhappy moods lead to a retrospective bias to mind wandering. Cogn Emot. 25:1481-90.