I previously did a post (last week) regarding a paper published in Science that found in humans if you warm their hands they both judge strangers as ‘warmer’ but also more willing to pick up a gift for a friend instead of for themselves. Additionally, cooling the subjects hands had the opposite results.
I proposed that possibly the old saying – cold hands warm heart (and vice versa) needs to put to rest. However, I have been doing some rethinking and possibly I spoke in haste.
One thing that got me rethinking about this idea is many of the most warm hearted individuals I know are females with constantly cool to cold hands.
In the cited study they manipulated the baseline temperature of these subjects. So maybe it doesn’t matter if you are cold or warm handed – but rather what is important is the change in hand temperature. An alteration in homeostasis to either colder or warmer will influence your thoughts of strangers, or you likelihood in gift giving.
What part of the brain is involved in detecting temperature changes in our hands – the insula (insular cortex). Interestingly, the insula has also been tied into components of the system of trust and empathy (here, here and here). But since the insula, involved in trust and empathy, also plays an important role in detecting changes (for homeostasis purpose) in temperature (e.g. hand) it is possible that since it is more likely for a naturally cool hand to be warmed up, as compared to an already hot hand, therefore maybe there is a bit of truth to the saying; cold hands warm heart.
(The insula is also involved with disgust, possibly including moral disgust. I could probably write a hundred blog posts just on the insula but I won’t (currently) bore you readers).
Now some might argue that I am making too much out of this one somewhat oddball study even though it was published in the high impact Science journal. However, there are at least another papers that touches on a similar theme.
Zhong and Leonardelli (2008) examined social inclusion and exclusion and how it affected subjects ‘coldness’ (via livescience). In this first study they asked subjects to recall being rejected from a social group – such as a club, and also a time when they were accepted. Then they asked the subjects to perform an unrelated task immediately after their imagination of the two circumstance of estimating the temperature of the room. While the actual room temperature did not change those that imagined being rejected by a group on average estimate the room temperature at 71 degrees, while the group that imagined acceptance reported 75 degrees (a statistical significance difference). Four degree difference while not a huge difference does support the cool and warm feeling we might feel depending on being accepted or rejected.
In the second study the researchers used a computer simulated game of catch among a group of participants where the program could be rigged to exclude a subject (making them feel socially isolated) or include them in the game of catch. After the simulated game of catch the researchers offered the participants a range of drinks: crackers, apple, hot soup, cold coke, hot coffee. The subjects that were excluded were more likely to pick a hot food/beverage compared to those that were included in the game of catch. This would suggest that when we feel rejected we do feel cold and reach out for something warm to comfort us.
Take home considerations:
Social isolation, in its various forms, appears to make a person judge their environment as colder and for them to feel cold and isolated and therefore seek out nourishment in the form of warm food and beverages to comfort themselves.
And on the flip side if a peripheral component of your body (e.g. hands) are warmed or cooled it changes your judgment of strangers and your gift giving.
Your actual baseline hand temperature might have nothing to do with how you judge strangers or your kindness – but it is the change in hand temperature that possibly signals through the insula which affects our social outlook.
Update: Check out this article on the brain biology of social isolation.