Yes, heat can negatively affect cognitive performance, including functions related to IQ.
Studies indicate that even a small increase in ambient temperature can impair cognitive functions such as memory, reaction time, and executive functioning. One investigation, for example, found that a four-degree increase in temperature led to an average 10% drop in performance on tests evaluating these abilities. This reduction in cognitive performance suggests a potential decrease in effective IQ when exposed to higher temperatures.
The mechanism behind this effect is believed to involve how heat stress impacts the brain. Higher temperatures can lead to:
- Reduced Cerebral Blood Flow: Heat stress can affect blood flow to the brain, potentially impairing neuronal function.
- Impaired Neural Processing: Elevated temperatures can interfere with the efficiency of neural circuits.
- Increased Physiological Stress: The body's response to heat stress can divert resources away from cognitive processing.
While the term "IQ" is a complex construct, performance on cognitive tests used to assess IQ can be negatively impacted by heat. Therefore, while heat might not permanently alter someone's underlying intelligence, it can temporarily impair cognitive functions, resulting in lower test scores and reduced cognitive effectiveness.
