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How Heat Affects our Behavior and Decision-Making

We’ve all experienced those hot summer’s days, when you’re sweating through your clothes and it seems unbearable to move even one more inch than necessary. Those days when everybody seems especially annoying and all you want to do is go home, crank up the AC, and cool down. 

As climate change marches full steam ahead, heatwaves are becoming more frequent and more intense.1 Many experts have sounded the alarm about how a warming planet is likely to affect our physical health, putting vulnerable people at increased risk of heat-related illnesses such as cardiovascular disease and heat stroke. 

But another, often-overlooked consequence of climate change is the effect this extra heat will have on our decision-making processes. If you’ve noticed that you feel more irritable in the warmer months, rest assured that it’s not just you. As it turns out, social scientists have documented this phenomenon, dubbing it the heat hypothesis. The theory posits that hot weather can increase angry, aggressive, and even violent behavior.2,3,4,5

If we’re going to prevent the worst of the climate crisis from hitting us, we need to change our behavior, and fast. But given what we know about climate change and all the human elements that contribute to it, could the hot weather itself be an obstacle to making progress on this front? And what other consequences will a warming planet have on our decision-making?

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When temperatures run high, so do tempers

Crime is at its peak during hot summer months.6,7 This is partially because people tend to congregate more during warm months, and thus have more opportunities to bristle. 

But there’s more to the story than just that. Being in uncomfortably hot environments has been found to breed aggressive thoughts, while also reducing positive emotions like delight and contentedness.8,9 Hot weather is also associated with more emergency room visits for mental health crises, suicides, and poor mental health days.10 When we’re feeling angry at something intangible (like an inescapable heatwave), we tend to displace it onto something we can get mad at — like the barista who got your order wrong, for example.11

Heat has measurable effects on our bodies, too: it can increase testosterone, heart rate, and additional metabolic reactions that turn on our sympathetic nervous system (the system responsible for our “fight or flight” responses).11 

Possibly as a result of these physiological changes, hot weather is also linked to worse mental health outcomes. A temperature increase of 1°C (1.8°F) is associated with a distinguishable increase in the presentation of neurotic and anxiety disorders, schizophrenia, and other mood disorders.12

This is your brain on anger

When unbearable heat makes us angry, what kind of impact does that have on our decision-making?

It turns out that people who are angry tend to make quick decisions and are less likely to stop and consider their options.13 While this emotion doesn’t impede on other important facets of decision-making like decision speed,14 it does negatively impact the strategy, objectivity, and rationality of those decisions.13

Moreover, because angry people are more likely to make choices faster than their cool and collected counterparts, they are also more prone to relying on heuristics when processing information.15,16,17,18,19,20 In using heuristics, much of the uncertainty we typically feel in any given judgment fades, giving way to unwarranted optimism,20,21 overconfidence, and an inflated sense of control.13 

For example, picture someone who decides to speed through a red traffic light on a hot day because they want to get to their destination sooner. If the weather were more temperate, perhaps they would remember the risks of running a red light (hitting a car or pedestrian, getting a ticket, etc), but in their current state, they feel confident that their risk of consequences is much closer to zero than normal.

Is there any hope for the future?

Projections for the future of climate change can seem pretty bleak. For example, the World Health Organization estimates that by 2050, extreme heat waves could kill more than 255,000 people across the globe each year.22 

Fortunately, we still have time to manage the damage before it’s too late using proven strategies to manage our heat-induced anger. With proper behavior change, we can address the climate crisis. A recent study found that some of the strongest ways to mitigate climate catastrophe are by having a focus on high-impact behaviors (for example, habits, defaults, and social influence) and using interdisciplinary approaches to design interventions targeting a diverse array of behavioral barriers.23 While this study is tailored toward researchers and high-level decision-makers, there are ways we can address climate change at a micro level.

How to avoid anger

Here are some actionable steps that you can take to manage the angry feelings that arise during hot weather.

Check in with yourself

When the temperature rises, the first step is to monitor how you’re feeling. Check in with yourself and see whether your heart rate is increasing, you’re sweating more than normal, or are thinking more negative things than usual. These are all warning signs that anger is brewing. At the same time, identify if there’s anything that your body is needing that might contribute to your frustration. Do you need water? Is your blood sugar low?24

Learn your triggers

Secondly, keep track of the things that set you off when you’re in a bad mood. This could be anything from slow wifi, to someone speeding through a red traffic light, to the simple fact of being uncomfortable. Try to mitigate these triggers, for example playing music that makes you feel happy while driving, or doing some stretches while waiting for the wifi to load. 

Redirect your frustration

When all else fails, look for ways to channel your anger. You could paint, exercise, or even listen to music that is somehow cathartic. Any of these can help you calm.

Keeping cool in the climate crisis

As temperatures continue to rise, it’s important to take care of yourself while also keeping the environment in mind. While much of what’s impacting climate change is out of our hands, there are steps we can take and robust ways of addressing our heat-induced anger. In order to show up for the world, we must be aware of our own behaviors and the alternatives that are available to us.

References

  1. Center for Climate and Energy Solutions. (2022, July 27). Heat Waves and Climate Change. Retrieved September 8, 2022, from https://www.c2es.org/content/heat-waves-and-climate-change/
  2. Allen, J. J., Anderson, C. A., & Bushman, B. J. (2018, February). The General Aggression Model. Current Opinion in Psychology, 19, 75–80. https://doi.org/10.1016/j.copsyc.2017.03.034 
  3. Anderson, C. A. (1989, July). Temperature and aggression: ubiquitous effects of heat on occurrence of human violence. Psychological Bulletin, 106(1), 74–96. https://doi.org/10.1037/0033-2909.106.1.74 
  4. Anderson, C. A., & Anderson, D. C. (1984, January). Ambient temperature and violent crime: tests of the linear and curvilinear hypotheses. Journal of Personality and Social Psychology, 46(1), 91–97. https://doi.org/10.1037//0022-3514.46.1.91 
  5. Krenzer, W. L. D., & Splan, E. D. (2018, January). Evaluating the heat-aggression hypothesis: The role of temporal and social factors in predicting baseball related aggression. Aggress Behav, 44(1), 83–88. https://doi.org/10.1002/ab.21726
  6. Ceccato, V. (2005, September). Homicide in São Paulo, Brazil: Assessing spatial-temporal and weather variations. Journal of Environmental Psychology, 25(3), 307–321. https://www.sciencedirect.com/science/article/abs/pii/S0272494405000393?via%3Dihub
  7. Breetzke, G. D. (2011, February 10). Seasonal Assault and Neighborhood Deprivation in South Africa: Some Preliminary Findings.  Environment and Behavior, 44(5). https://doi.org/10.1177/0013916510397758
  8. Miles-Novelo, A., & Anderson, C. A. (2019, January). Climate Change and Psychology: Effects of Rapid Global Warming on Violence and Aggression. Current Climate Change Reports, 5, 36–46. https://doi.org/10.1007/s40641-019-00121-2
  9. Plante, C., Allen, J. A., & Anderson, C. A. (2017, April). Likely Effects of Rapid Climate Change on Violence andConflict. Oxford Research Encyclopedia of Climate Science. https://doi.org/10.1093/acrefore/9780190228620.013.344
  10. Mullins, J. T., & White, C. (2019, December). Temperature and mental health: Evidence from the spectrum of mental health outcomes. Journal of Health Economics, 68, 102240. https://doi.org/10.1016/j.jhealeco.2019.102240
  11. Burnett, D. (2018, February 14). Cruel Summer: how hot weather makes people angrier. The Guardian. Retrieved September 8, 2022, from https://www.theguardian.com/science/brain-flapping/2015/jul/03/summer-hot-weather-anger-psychology
  12. Liu, J., Varghese, B. M., Hansen, A., Xiang, J., Zhang, Y., Dear, K., Gourley, M., Driscoll, T., Morgan, G., Capon, A., & Bi, P. (2021, August). Is there an association between hot weather and poor mental health outcomes? A systematic review and meta-analysis. Environment International, 153, 106533. https://doi.org/10.1016/j.envint.2021.106533
  13. Lerner, J. S., & Tiedens, L. Z. (2006). Portrait of the angry decision maker: how appraisal tendencies shape anger’s influence on cognition. Journal of Behavioral Decision Making, 19(2), 115–137. https://doi.org/10.1002/bdm.515
  14. Meissner, P., Poensgen, C., & Wulf, T. (2021, August). How hot cognition can lead us astray: The effect of anger on strategic decision making. European Management Journal, 39(4), 434–444. https://doi.org/10.1016/j.emj.2020.09.010
  15. Bodenhausen, G. V., Sheppard, L. A., & Kramer, G. P. (1994, January). Negative affect and social judgment: The differential impact of anger and sadness. European Journal of Social Psychology, 24(1), 45–62. https://doi.org/10.1002/ejsp.2420240104
  16. Lerner, J. S., Goldberg, J. H., & Tetlock, P. E. (1998, June). Sober Second Thought: The Effects of Accountability, Anger, and Authoritarianism on Attributions of Responsibility. Personality and Social Psychology Bulletin, 24(6), 563–574. https://doi.org/10.1177/0146167298246001
  17. Small, D. A., & Lerner, J. S. (2008, April). Emotional Policy: Personal Sadness and Anger Shape Judgments about a Welfare Case. Political Psychology, 29(2), 149–168. https://doi.org/10.1111/j.1467-9221.2008.00621.x
  18. Tiedens, L. Z. (2001). The Effect of Anger on the Hostile Inferences of Aggressive and Nonaggressive People: Specific Emotions, Cognitive Processing, and Chronic Accessibility. Motivation and Emotion, 25(3), 233–251. https://doi.org/10.1023/a:1012224507488
  19. Tiedens, L. Z., & Linton, S. (2001). Judgment under emotional certainty and uncertainty: The effects of specific emotions on information processing. Journal of Personality and Social Psychology, 81(6), 973–988. https://doi.org/10.1037/0022-3514.81.6.973
  20. Litvak, P. M., Lerner, J. S., Tiedens, L. Z., & Shonk, K. (2009, December 21). Fuel in the Fire: How Anger Impacts Judgment and Decision-Making. International Handbook of Anger, 287–310. https://doi.org/10.1007/978-0-387-89676-2_17
  21. Lerner, J. S., & Keltner, D. (2001). Fear, Anger, and Risk. Journal of Personality and Social Psychology, 81(1), 146–159. https://doi.org/10.1037//O022-3514.81.1.146
  22. Underwood, E. A. M. (2021, June 23). How to Prevent Air Conditioners from Heating the Planet. Scientific American. Retrieved September 8, 2022, from https://www.scientificamerican.com/article/how-to-prevent-air-conditioners-from-heating-the-planet/
  23. Whitmarsh, L., Poortinga, W., & Capstick, S. (2021, December). Behaviour change to address climate change. Current Opinion in Psychology, 42, 76–81. https://doi.org/10.1016/j.copsyc.2021.04.002
  24. Communications and Marketing. (2022, July 20). 8 ways to manage your anger when the temperature rises. Vanderbilt University. Retrieved September 8, 2022, from https://news.vanderbilt.edu/2018/07/20/8-ways-to-manage-your-anger-when-the-temperature-rises/

About the Author

Lindsey Turk's portrait

Lindsey Turk

Lindsey Turk is a Summer Content Associate at The Decision Lab. She holds a Master of Professional Studies in Applied Economics and Management from Cornell University and a Bachelor of Arts in Psychology from Boston University. Over the last few years, she’s gained experience in customer service, consulting, research, and communications in various industries. Before The Decision Lab, Lindsey served as a consultant to the US Department of State, working with its international HIV initiative, PEPFAR. Through Cornell, she also worked with a health food company in Kenya to improve access to clean foods and cites this opportunity as what cemented her interest in using behavioral science for good.

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