Environmental temperature—heat, in particular—has been shown to influence our tendency toward aggressive and violent acts. It can also tweak our emotional state, making us more likely to reach (no pun intended) a psychological boiling point.
High temperatures have been linked to crime waves and waves of violence against specific groups; often cultural out-groups.
High temperatures seem to be associated with higher levels of distrust against perceived Others, and an increased likelihood of doing illegal, immoral, or violent things, often in support of one’s own survival or perceived tribe.
There’s even evidence that we see higher levels of autocratic politics in areas that are hotter, on average, and higher levels of collectivistic politics in areas that don’t or seldom suffer from heat waves.
There are a lot of “maybes” and variables that have had to be controlled for in the research that’s been done in this space, and even with all that hedging and accounting for things that might be influencing the data beyond just temperature, there’s still quite a lot that might not line up as more data rolls in from new locations as climactic belts shift (roughly northward) and new areas suffer from heat waves that were, until recently, relegated to regions generally south of them.
That said, there are some compelling reasons to think these numbers might be accurate. And while not a silver-bullet explanation for why some societies suffer from perennial authoritarianism and crime and out-group prejudice, it may help us understand one facet of the larger collection of variables that seem to lock-in such distinctions.
One component of this larger theory is a measure of what’s called “climato-economic livability,” which basically asks “how latently survivable is a given region, and what percentage of a culture’s resources have to be spent on bare-bones survival because of the climate?”
This measure was developed by figuring out which regions have the proper resources (in terms of food and drinkable water, but also temperatures that are survivable and allow folks to be mentally and physically functional, even if they don’t have the resources to build thick walls or air conditioners) and then identifying dominant political, cultural, and other such traits within each region.
In general—not universally, but in a statistically significant way—it would seem that you can carve up the world by climate zone and the availability of local resources (those which, importantly, are accessible by locals; which isn’t always the case, especially in post-colonial regions) and that’ll give you a decent idea of who’s doing well and who isn’t.
This isn’t destiny, and there are many outliers, but this theory posits that there’s a correlation between where people are settled and their outcomes according to a variety of measurements. Government structures, cultural mores, individual influences, and the like can all influence this foundation, but the foundation can also influence those potential influences.
Another theory, this one more biological in nature, posits that we’re actually less capable of being generous, open, empathic, and pro-social when we’re very hot; to the point where it’s technically possible for us to want to help someone else, but to not be able to force ourselves to do it, because the perceived effort of providing such aid just feels too psychologically overwhelming.
There are two main theories that make up this larger theory: one that suggests the insula—a small region within the cerebral cortex—may play a role in this shift from prosocial to antisocial tendencies, and another that proposes our internal chemistries are to blame.
The insula-oriented theory is predicated on the notion that this brain-region might mediate our trust processes, and might itself be influenced by temperature; and this supposition is supported by a small body of research that shows people who are cold perform better in trust-related exercises than people who are uncomfortably warm.
Chemical-focused theories posit that one of the many chemicals that regulate our behaviors and bodily functions are adjusted by temperature—especially heat—in such a way that our other functions are adjusted, in kind, which thus changes our posture toward others.
There’s some research focused on vasopressin, which helps regulate body temperature and which may tweak other things in order to make that regulation happen, but some of the most thorough work exploring this angle, thus far, has been oriented around oxytocin: a hormone that does a lot of things, but perhaps most famously regulates (and incentivizes) social bonding in various ways. This has earned oxytocin the popular press monicker “the love hormone,” because it plays a dominant role in feelings like empathy, affection, love, and a general sense of connection with other people.
The theory is that our oxytocin levels are thrown off by high temperatures and the regulatory processes that trigger inside our bodies to keep our brains and other organs functioning correctly as we try to expel all that extra heat (which is very energy intensive).
This drop in oxytocin makes us less likely to empathize with strangers, less likely to feel inclined to help others, more likely to fall back on in-group, tribal affiliations for protection (rather than latently perceiving more people, whomever they might be, to be “one of us”), and more likely to be on a hair-trigger for violence in support of our in-groups and ourselves.
In short: we seem to become a lot less prosocial when hot, because our bodies are too busy keeping us alive to incentivize us to bond with others—which is also a survival mechanism, but not as pressing as the immediate concern of not dying from the heat.
This theory obviously has a lot of potentially uncomfortable ramifications, and is far from a proven fact. But it is interesting to consider how something as simple as environmental temperature might temporarily or consistently distort our perception of things so fundamentally.
Enjoying Brain Lenses? You might also enjoy my news analysis podcast, Let’s Know Things and my daily news summary, One Sentence News.
The Brain Lenses podcast is available at brainlenses.com or wherever you get your podcasts.