How hunger and cold make us judge people more harshly

HostMost of us have had that feeling where we're stuck in a freezing office or we have skipped lunch, and suddenly every little thing our coworkers do is just the worst. We usually just call it being cranky, but there's actually something much deeper happening in the brain when our bodies are unhappy. I want to look at why a drop in temperature or an empty stomach can actually turn us into harsher judges of the people around us.

GuestIt really comes down to how the brain manages its bank account. Thinking is expensive. To be fair, to be kind, or to really try and see things from someone else's point of view takes a lot of energy. It's what we call a high-cost task. Now, your brain has one main job above everything else, and that's keeping you alive. If you're shivering because it's too cold, or if your blood sugar is crashing because you haven't eaten, your brain goes into a sort of emergency mode. It starts cutting back on spending in areas it thinks aren't vital. Sadly, being a nice, understanding person is often the first thing to get its budget cut when the body is trying to save fuel.

HostSo it's not just that I'm in a bad mood, it's that my brain is literally turning off the parts that help me be nice?

GuestIn a way, yes. Think of it like a house during a power outage. You turn off the big TV and the fancy lights so you can keep the fridge running. When you're hungry, your brain focuses on the basics. It relies on shortcuts. These shortcuts are often based on snap judgments or old stereotypes. We don't have the spare fuel to stop and think, well, maybe that person cut me off in traffic because they're having a bad day. Instead, our brain just takes the easy route and decides they're a jerk. We lose the ability to do that extra bit of mental work that lets us be graceful or patient with others.

HostThat sounds like we're just at the mercy of our stomachs, but I struggle to see how being chilly makes me think someone is a bad person. Those feel like two completely different things.

GuestIt feels that way because we like to think our thoughts are separate from our skin and bones, but they're tied together tightly. There's this famous idea about social warmth. When we describe a person as warm or cold, we're not just using a pretty metaphor. The parts of the brain that handle physical touch and temperature are right next to the parts that handle how we feel about other people. In some well-known tests, people who were asked to hold a cup of iced coffee for a minute ended up rating a stranger as being much colder and less friendly than people who were given a warm cup of coffee to hold. When your body feels cold, it sends a signal that the world is a harsh, unforgiving place, and you start to see the people in that world through that same lens.

HostI have heard about that coffee study, but I also heard it was hard for other scientists to get the same results. Is it really that simple?

GuestYou're right to be skeptical. Some of those specific small studies are still being debated. But the bigger picture, the link between our body and our mind, has a mountain of evidence behind it. Think about the stakes in a courtroom. There was a study of judges in Israel that looked at over a thousand rulings. They found that judges were much more likely to give someone a break and grant parole right after they had their morning snack or their lunch. As the time dragged on and the judges got hungrier, the chances of a prisoner getting a favorable ruling dropped almost to zero. Once the judges ate, the rate of being kind jumped right back up. When they were low on gas, they defaulted to the safest, easiest answer, which was usually just saying no.

HostThat's terrifying. We're talking about people's lives being decided by whether a judge had a granola bar or not.

GuestIt's a harsh reality. When we're low on resources, we also tend to see other people as a threat or a burden. If I'm starving, another person isn't a friend, they're a rival for the last bit of food. If I'm freezing, I don't want to spend my energy helping you with your problems because I need all that energy just to stay upright and warm. We become more selfish because we're in survival mode. Our circle of care shrinks until it only includes ourselves. We start to see the world as a place of scarcity, and in a world like that, being harsh is a way to protect what little we have left.

HostIt makes me wonder if we even have a steady personality at all, or if we're just a collection of reactions to how much we ate for breakfast.

GuestWell, we certainly like to believe we have a solid character that stays the same, but the data shows we're much more fluid than that. Our sense of right and wrong, and how we treat our neighbors, is built on top of a physical foundation. If that foundation is shaky because we're tired, cold, or hungry, the whole building starts to lean. The most interesting part is that we almost never realize it's happening. We truly believe the person across from us is being annoying, rather than realizing our own blood sugar is just low.

HostThe next time a coworker seems particularly frustrating, it might be worth checking if the thermostat is too low or if it's just getting close to the lunch hour.

GuestA sandwich and a warm sweater might do more for world peace than we would ever like to admit.

HostThe thermometer on the wall and the snack in the drawer are doing a lot more work for our relationships than we think.