The True Spark of Your Anger
Written by Joanne Liu
Edited by Numa Islam
April 5, 2024
Edited by Numa Islam
April 5, 2024
Health and Wellness
A Google search of the term “anger” will return countless images of people with red faces and steam pouring out of their ears. Strengthening this imagery, common English terms like “hot-headed” and “hot-tempered” associate high temperatures with rage and hostility. This poses the question: is the connection between heat and anger legitimate and science-backed, or is it merely illusory?
To answer this question, Kenrick & MacFarlane (1986) investigated the intensity of horn honking at a busy Phoenix intersection from April to August, when perceived temperatures ranged from 88° to 116° Fahrenheit. For each session of the study, a confederate, or a researcher’s aide posing as a participant, remained stationary at a green light until the light turned red, when the confederate took a (legal) right turn onto a neighboring street (American Psychological Association, n.d.; Kenrick & MacFarlane, 1986). While the confederate was stopped, an observer recorded the reactions of the drivers trapped behind the confederate (Kenrick & MacFarlane, 1986). The researchers discovered a positive correlation between temperature and the number of horn honks, especially among drivers who had their windows down (Kenrick & MacFarlane, 1986). Additionally, temperature was positively associated with the amount of time spent leaning on the horn (Kenrick & MacFarlane, 1986). To demonstrate, at temperatures over 100° Fahrenheit, many drivers leaned on their horn for over 50% of the green light interval, whereas at temperatures below 90°, no drivers did so (Kenrick & MacFarlane, 1986).
Recent studies reinforce these findings. Notably, Mukherjee & Sanders (2021) discovered a positive correlation between heat and violence among the incarcerated in the Mississippi prison system. In fact, on days with an average temperature above 80° Fahrenheit, the number of daily violent acts increased by approximately 20% above the baseline (Mukherjee & Sanders, 2021). Furthermore, drawing on daily crime data from the City of Los Angeles, Heilmann et al. (2021) documented a positive relationship between the daily crime rate and the daily maximum temperature. Specifically, for every 1° Fahrenheit increase in daily maximum temperature, the daily crime rate tended to increase between 0.11 and 0.14% (Heilmann et al., 2021).
The association between heat and aggression could have a scientific explanation. Namely, in response to rising ambient temperatures, excess heat migrates to the skin’s surface to preserve core body temperature (Gaoua et al., 2012). However, this physiological response alters an individual’s subjective state by competing with the resources necessary for optimal cognitive performance (Gaoua et al., 2012). Moreover, Gaoua et al. (2011) identified a positive correlation between impulsivity and environmental temperature during a rapid visual processing test, and Rastegar et al. (2022) noted that heat stress decreased accuracy on a working memory performance test. Therefore, the combination of a warm environment, an altered subjective state, increased impulsivity, and an increased likelihood of errors could increase the chance of violent outbursts.
With average temperatures skyrocketing as a result of climate change, the number of violent incidents will only increase in the future. Along with increased temperature control in all buildings, further efforts to mitigate rapid climate change need to be implemented to promote public health and safety.
Works Cited
American Psychological Association. (n.d.). APA Dictionary of Psychology. Retrieved October 23, 2023, from https://dictionary.apa.org/confederate
Gaoua, N., Grantham, J., Racinais, S., & El Massioui, F. (2012). Sensory displeasure reduces complex cognitive performance in the heat. Journal of Environmental Psychology, 32(2), 158-163. https://doi.org/10.1016/j.jenvp.2012.01.002
Gaoua, N., Racinais, S., Grantham, J., & El Massioui, F. (2011). Alterations in cognitive performance during passive hyperthermia are task dependent. International Journal of Hyperthermia, 27(1), 1-9. https://doi.org/10.3109%2F02656736.2010.516305
Heilmann, K., Kahn, M. E., & Tang, C. K. (2021). The urban crime and heat gradient in high and low poverty areas. Journal of Public Economics, 197, Article 104408. https://doi.org/10.1016/j.jpubeco.2021.104408
Kenrick, D. T., & MacFarlane, S. W. (1986). Ambient Temperature and Horn Honking: A Field Study of the Heat/Aggression Relationship. Environment and Behavior, 18(2), 179-191. https://doi.org/10.1177/0013916586182002
Mukherjee, A., & Sanders, N. J. (2021). The Causal Effect of Heat on Violence: Social Implications of Unmitigated Heat Among the Incarcerated. National Bureau of Economic Research, Article 28987. https://doi.org/10.3386/w28987
Rastegar, Z., Ghotbi Ravandi, M. R., Zare, S., Khanjani, N., & Esmaeili, R. (2022). Evaluating the effect of heat stress on cognitive performance of petrochemical workers: A field study. Heliyon, 8(1), Article e08698. https://doi.org/10.1016%2Fj.heliyon.2021.e08698
To answer this question, Kenrick & MacFarlane (1986) investigated the intensity of horn honking at a busy Phoenix intersection from April to August, when perceived temperatures ranged from 88° to 116° Fahrenheit. For each session of the study, a confederate, or a researcher’s aide posing as a participant, remained stationary at a green light until the light turned red, when the confederate took a (legal) right turn onto a neighboring street (American Psychological Association, n.d.; Kenrick & MacFarlane, 1986). While the confederate was stopped, an observer recorded the reactions of the drivers trapped behind the confederate (Kenrick & MacFarlane, 1986). The researchers discovered a positive correlation between temperature and the number of horn honks, especially among drivers who had their windows down (Kenrick & MacFarlane, 1986). Additionally, temperature was positively associated with the amount of time spent leaning on the horn (Kenrick & MacFarlane, 1986). To demonstrate, at temperatures over 100° Fahrenheit, many drivers leaned on their horn for over 50% of the green light interval, whereas at temperatures below 90°, no drivers did so (Kenrick & MacFarlane, 1986).
Recent studies reinforce these findings. Notably, Mukherjee & Sanders (2021) discovered a positive correlation between heat and violence among the incarcerated in the Mississippi prison system. In fact, on days with an average temperature above 80° Fahrenheit, the number of daily violent acts increased by approximately 20% above the baseline (Mukherjee & Sanders, 2021). Furthermore, drawing on daily crime data from the City of Los Angeles, Heilmann et al. (2021) documented a positive relationship between the daily crime rate and the daily maximum temperature. Specifically, for every 1° Fahrenheit increase in daily maximum temperature, the daily crime rate tended to increase between 0.11 and 0.14% (Heilmann et al., 2021).
The association between heat and aggression could have a scientific explanation. Namely, in response to rising ambient temperatures, excess heat migrates to the skin’s surface to preserve core body temperature (Gaoua et al., 2012). However, this physiological response alters an individual’s subjective state by competing with the resources necessary for optimal cognitive performance (Gaoua et al., 2012). Moreover, Gaoua et al. (2011) identified a positive correlation between impulsivity and environmental temperature during a rapid visual processing test, and Rastegar et al. (2022) noted that heat stress decreased accuracy on a working memory performance test. Therefore, the combination of a warm environment, an altered subjective state, increased impulsivity, and an increased likelihood of errors could increase the chance of violent outbursts.
With average temperatures skyrocketing as a result of climate change, the number of violent incidents will only increase in the future. Along with increased temperature control in all buildings, further efforts to mitigate rapid climate change need to be implemented to promote public health and safety.
Works Cited
American Psychological Association. (n.d.). APA Dictionary of Psychology. Retrieved October 23, 2023, from https://dictionary.apa.org/confederate
Gaoua, N., Grantham, J., Racinais, S., & El Massioui, F. (2012). Sensory displeasure reduces complex cognitive performance in the heat. Journal of Environmental Psychology, 32(2), 158-163. https://doi.org/10.1016/j.jenvp.2012.01.002
Gaoua, N., Racinais, S., Grantham, J., & El Massioui, F. (2011). Alterations in cognitive performance during passive hyperthermia are task dependent. International Journal of Hyperthermia, 27(1), 1-9. https://doi.org/10.3109%2F02656736.2010.516305
Heilmann, K., Kahn, M. E., & Tang, C. K. (2021). The urban crime and heat gradient in high and low poverty areas. Journal of Public Economics, 197, Article 104408. https://doi.org/10.1016/j.jpubeco.2021.104408
Kenrick, D. T., & MacFarlane, S. W. (1986). Ambient Temperature and Horn Honking: A Field Study of the Heat/Aggression Relationship. Environment and Behavior, 18(2), 179-191. https://doi.org/10.1177/0013916586182002
Mukherjee, A., & Sanders, N. J. (2021). The Causal Effect of Heat on Violence: Social Implications of Unmitigated Heat Among the Incarcerated. National Bureau of Economic Research, Article 28987. https://doi.org/10.3386/w28987
Rastegar, Z., Ghotbi Ravandi, M. R., Zare, S., Khanjani, N., & Esmaeili, R. (2022). Evaluating the effect of heat stress on cognitive performance of petrochemical workers: A field study. Heliyon, 8(1), Article e08698. https://doi.org/10.1016%2Fj.heliyon.2021.e08698
Image Source: “Mad formal executive man yelling at camera” by Andrea Piacquadio licensed under Pexels License