How Sleep Deprivation Affects Decisions

On a December morning in 2013, a train engineer named William Rockefeller took a curve on New York's Hudson rail line at nearly eighty miles an hour. The posted limit was thirty-five. He hit the brakes, but too late. Four people died and sixty were injured when the train derailed (03:10). Investigators first called it operator error. Later it came out that Rockefeller had likely fallen asleep at the controls. He also had sleep apnea, a disorder in which the airway closes during the night and a person is startled awake, sometimes hundreds of times per hour, without ever fully remembering it (05:32).

University of Washington sleep researcher Chris Barnes has spent years studying cases like this one, and a nearly identical UK crash in 2001 in which a driver named Gary Hart fell asleep at the wheel, setting off a chain of events that killed ten people (08:33). Barnes argues that blaming the individual is too easy. "We usually prefer simple, easy answers," he says. "We don't often ask the question, okay, why did that human error occur?" (09:21). Rockefeller and Hart were not reckless men with long records of accidents. They were ordinary people whose sleep debt, work schedules, and undiagnosed disorders stacked together until the odds caught up with them.

Barnes knows the feeling personally. In 2019, with newborn twins and a three-year-old at home, he got a 3 a.m. call that his father might be dying. He drove an hour to the hospital, learned his father was stable, and drove home exhausted. On the freeway, he fell asleep for what he estimates was three to five seconds, at highway speed (14:24).

"In the multiverse, some swath of that multiverse, I am the villain in some family's story." — Chris Barnes (15:21)

That line captures something the data confirm at scale. Barnes and a co-author at the National University of Singapore found that car crashes spike in Singapore and Taiwan the morning after popular European soccer matches, because fans stay up into the early hours to watch games broadcast at a reasonable hour across the ocean but an unreasonable one at home (16:15). The effect grows with how popular the teams are. It is not an anecdote. It shows up in taxi company records and in nationwide crash data alike.

What makes sleep loss so dangerous is not just fatigue. Barnes's research finds that sleep deprivation specifically damages decision-making in situations that are new or unexpected, the kind where a person cannot simply fall back on habit (22:34). It also erodes something subtler: moral awareness, the basic recognition that a decision has an ethical dimension at all. "When people are sleep deprived, their moral awareness is lower," Barnes says, "so they're less likely to even appreciate that there's a moral aspect to the decision" (25:13). In his studies, the same person behaves more or less ethically on different days, depending in part on how they slept the night before (24:31). The effect is not trivial even at small doses. Barnes points to nap studies showing that ten or fifteen minutes of sleep is enough to move the needle on outcomes like performance (24:52).

The stakes rise sharply in industrial settings. In 2005, a BP refinery in Texas City exploded after fuel vented and ignited, killing fifteen workers and injuring 180. One worker involved had accumulated 43 hours of sleep debt from a month of 12-hour shifts stacked on top of two-hour commutes (28:26). Chernobyl and Three Mile Island, the two most infamous nuclear accidents, both began between 1:30 and 4 a.m., the hours when the body's circadian rhythm, its internal 24-hour clock, pushes hardest toward sleep (29:46). And Barnes's own research on a half million mining injuries over 25 years found a 5.6 percent spike in injuries the Monday after the spring shift to daylight saving time, even though mining happens underground, away from any change in daylight (34:33).

What the Body Clock Is Owed

Most adults need seven to nine hours of sleep, Barnes says, and very few of the people who think they are an exception actually are (38:59). Screens complicate things further: blue light suppresses melatonin, the hormone that signals the body to wind down, which is why using a phone at night can quietly steal the sleep needed to be sharp the next day (42:13). Barnes is careful to note that blue-light-filtering glasses are not a cure, just a partial fix.

He also points to a cultural habit that works against all of this: bragging about sleep deprivation as a badge of status. In his research, men who brag about getting little sleep are seen as stronger, while women who do the same are seen as more self-sacrificing. Either way, the behavior gains social credit even though it predicts worse ethics, worse decisions, and more injuries (43:30). The dynamic helps explain why a problem this well documented remains so hard to fix. The data says rest. The culture says push through.

The Myth of the Broken Body

Pain, it turns out, runs on a similarly misunderstood logic. Psychologist Rachel Zoffness, who teaches at the University of California, San Francisco, and wrote the book Tell Me Where It Hurts: The New Science of Pain and How to Heal, argues that pain is never purely a biological signal. "One of the biggest myths we've been sold is that pain is a purely biomedical problem," she says, "something to do just with anatomy and physiology, that requires a purely biomedical solution" (57:59). She calls pain biopsychosocial, meaning it emerges from three overlapping sources: biology (tissue, inflammation, genetics), psychology (emotion, fear, belief), and social circumstances (relationships, stress, support).

The social piece sounds like the strangest claim until a listener named Bruce describes his own experience. He had chronic back pain for 25 years; his wife had chronic migraines. They divorced. Two years later, at a graduation, she noticed he was sitting upright instead of leaning back, the posture he had always needed for his back pain. Neither of them had had a symptom in a year and a half (59:44). Zoffness explains that healthy, low-conflict relationships raise levels of serotonin, dopamine, and the body's own natural opioids called endorphins, while turning down muscle tension and inflammation. Toxic, high-conflict relationships do the reverse: they raise inflammation, increase muscle tension, and reduce endorphin levels, all of which Zoffness summarizes simply as turning pain volume up in the brain (62:53).

Fear works through a related channel. A listener named Donna, who lived for years with a painful bladder condition called interstitial cystitis, described treating her own body as an enemy, living in constant fear of triggering a flare, until she reframed the pain as her brain being afraid rather than her body being broken. Within months, her life changed (65:35). Zoffness explains the mechanism: fear activates the amygdala, a brain region tied to threat detection, and an amygdala on high alert turns pain volume up, creating a loop where pain breeds fear and fear amplifies pain (66:56).

Perhaps the clearest illustration of the gap between damage and pain is Usain Bolt. The Jamaican sprinter grew up with a spine that twisted into an S-shape from scoliosis, and by the time he won eight Olympic gold medals, his right leg was half an inch shorter than his left. He ran anyway, largely without pain (78:36). "Hurt and harm, pain and damage are not the same thing," Zoffness says (77:34). The same disconnect shows up in endometriosis, a condition causing tissue overgrowth around the uterus: the amount of overgrowth often has little relationship to how much pain a woman reports (80:00).

None of this means pain is imagined. Zoffness is emphatic that pain is always real, never "all in your head." What she offers instead is a tool she calls pacing: patients identify how much of a beloved activity they can manage on a bad pain day, treat that low number as the starting baseline, and build up gradually, the way a runner trains for a marathon rather than attempting 26 miles on day one (83:55). She also describes a mental image called the pain dial, a volume knob in the brain and spinal cord. Focusing attention on a painful body part turns the dial up, because the brain's prefrontal cortex acts like a magnifier on whatever gets attention. Distraction, exercise, volunteering, or simply engaging with the world turns the dial back down (94:02).

Sleep debt and chronic pain look like unrelated problems: one is about staying awake too long, the other about a body that will not stop hurting. But both stories point to the same lesson. The brain is not a passive instrument that records what the body hands it. It actively shapes outcomes, for better or worse, depending on how well it is rested, how safe it feels, and what it has learned to expect. Barnes's research suggests better sleep policy, later school start times, saner shift schedules, no more disruptive spring clock changes, could prevent a measurable share of accidents and bad decisions. Zoffness's research suggests that treating chronic pain seriously means treating the whole person, not just the scan. Both arguments ask for the same shift in thinking: stop looking only at the broken part, and start looking at the system around it.