Winter Wakes Up Your Mind--and Warm Weather Makes it Harder to Think Straight: Scientific American

Winter Wakes Up Your Mind--and Warm Weather Makes it Harder to Think Straight: Scientific American

Warm temperatures, then, are more likely to deplete our resources?as our bodies work to maintain homeostasis, we use up large amounts of glucose. Because glucose is also used for mental processes, it may be that the physical demands imposed by excessive warmth reduce our capacity for cognitive functioning, thereby adversely affecting our decision-making abilities.

The researchers decided to test this apparent link between weather and complex decision-making in the lab by performing a series of experiments comparing participants? cognitive performance at two seemingly unremarkable temperatures: 19.4°C and 25° C People tend to be most comfortable at around 22.2° C so each temperature represented just ~3° C deviation from maximum comfort.

Despite this minimal deviation in temperature, the researchers found remarkable differences in cognitive functioning. In one lab study, participants were asked to proofread an article while they were in either a warm (25°) or a cool (19.4°) room. Participants in warm rooms performed significantly worse than those in cool rooms, failing to identify almost half of the spelling and grammatical errors (those in cool rooms, on the hand, only missed a quarter of the mistakes). These results suggest that even simple cognitive tasks can be adversely affected by excessive ambient warmth.

In a second study, the researchers showed similar effects for more complex cognitive calculations. In this study, another group of participants were asked to choose between two cell phone plans, again in either a warm or a cool room. One plan looked more attractive on the surface, but was actually more expensive; simple patterns of decision-making would therefore lead participants to choose the more expensive plan, whereas more complex analyses would lead participants to correctly choose the more cost-effective plan. Participants in the cool room made the correct choice over half the time; those in the warm room, on the other hand, made the correct choice only a quarter of the time. Warmer temperatures seemed to make participants more likely to rely on simplistic patterns of decision-making, which in turn led to inferior choices. These results suggest that complex decision-making, like simple cognitive tasks, is adversely affected by warm temperatures.


A third study suggests that warm surroundings may not just cause people to fail at complex decision-making?it may cause them to shy away from making these sorts of decisions in the first place. In this study, participants were placed in either a warm or a cool room and asked to choose between two products: an innovative one and a traditional one. Participants in warm rooms, relative to those in cool rooms, were much more likely to choose the traditional product?ostensibly because they did not have the cognitive resources necessary to evaluate the new information relevant to an innovative item.

These results do not mean, however, that people in warmer climates are reliably prone to making poorer decisions than those in cooler environments. Human beings are remarkably adaptive; we automatically acclimate to changes in ambient temperature and?given a bit of time?are capable of performing just as well in sweltering heat, frigid cold, and a climate-controlled office. It really does matter that you were on vacation when making your lottery decision; if you had been a native Alaskan or Floridian, the temperature would have made little, if any, difference. This research suggests that what does make a difference is slight deviations in temperature from an expected norm.