In other words, it's feel-good research that is complete hoooey.
Our local newspaper even ran with it. It basically makes the claim that holding a warm drink makes you think more positively about a stranger, so if you're meeting someone for date, you're well advised to go out for a cup of coffee — but make sure it's hot coffee, not iced coffee. On top of making people perceive another in a positive light, warmth also leads to increased generosity.
In the study, 41 participants held a cup of hot coffee or iced coffee before evaluating a stranger.
In a second experiment, participants handled hot or cold therapeutic pads in order to 'evaluate the product.' They were then given the choice of keeping a reward (Snapple drink, gift certificate to an ice cream) or giving it to a friend. People who handled the cold item chose to keep the reward 75 % of the time whereas those who handled the warm item chose to give it to a friend 56% of the time. Thus, warmth makes us feel good about others and also more generous.
Sort of. Here's what actually happened: The researchers apparently hired a confederate, a helper who is blind to the study's aims. This is common practice in social psychology experiments because it reduces the problem of what is known as 'experimenter effects' - in other words, biases unintentionally introduced by the experimenter. A blind-to-the-research confederate won't be able to unconsciously get the participants to behave according to expectations.
So, in this particular research, that hired confederate rode with each participant in an elevator up to the 'study room.' This is typical in psychology research too — participants are often greeted in one spot and taken to another where the actual research is conducted. Except that oftentimes, the real research is being conducted right from the beginning. Sneaky, sneaky.
In this research, the confederate asked each participant to hold a drink on the elevator on the way up to the study. Sometimes they passed off a cold drink and sometimes it was warm. And, that presumably is the only thing that varied, which is good in an experimental sense. In an experiment, you want everything else but what you're interested in to be exactly the same for everyone.
Except, if the participants could feel the temperature of the drink, so too could the confederate. And if the confederate can feel that some drinks are hot and some are not, wouldn't they be affected by the drinks too, and maybe behave differently on account of them? If so, then the results may not have been a cause of the drinks but rather the confederate's different behavior. That's not to say that the drink's temperature had no effect, but maybe that effect arises through the behavior of the other person.
That's nothing new. Smiling generates positive feelings. So does direct eye contact — and touch. One study decades ago found that waitresses who touched the diner while providing the bill got higher tips than those who didn't touch. Maybe the confederate made better eye contact, smiled and may have inadvertently touched the participants when passing off the hot beverage. Maybe the warm beverage put the confederate in a good mood too. Who knows, but since we don't know, I'm skeptical of the conclusions.
And did I mention 41 participants is a very small sample size? That makes the generalization of the results to the rest of the 99.999999999999% of the planet's inhabitants questionable.
What's more, something that leaves more serious doubts in my mind about the conclusions, is what time of year was this research conducted?
Connecticut in winter is a very different place from Connecticut in the summer. My guess is, that since student participants, the lab rats of social psychology research, are more plentiful and easier to rope into research during the winter than the summer, this research was probably conducted in the winter when a warm beverage would be a positive thing. In the 80 degree, 80 percent humidity summer — no way! Give me an iced beverage, please.
Finally, there is nothing new about the notion that positive stimuli elevate our mood. Back in the 60s this type of research was pretty popular and was conducted with all sorts of stimuli from scent ( fresh baked bread vs. socks), to lighting (natural vs florescent lighting), to type of furniture in an experimental room, all with exactly the kind of common sense discoveries you'd expect. So, it's just a little funny to hear Lawrence Williams, the lead author of the study, say, "We used to believe that our actions and feelings are unrelated to physical cues, but they are."
He's a good salesman and you have to be if you're promoting your research, you've got to make it sound better than it is, and he certainly has. After all, hundreds and thousands of news people picked up his story, including me.
Williams, who is no longer a graduate student at Yale, is — no surprise here — an assistant professor of marketing. It's also not a surprise to hear that he says this research has marketing implications.
Okay, so we're supposed to give everybody a warm cup of joe to better sell them stuff?
It's more cost effective to smile.
So, the moral of the story is - don't believe every study you read.
Experiencing physical warmth promotes interpersonal warmth
Lawrence E. Williams & John A. Bargh
Science 24 October 2008 322: 606-607