Evolutionary Psychology

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Robert Kurzban

The Evolutionary Psychology Blog

By Robert Kurzban

Robert Kurzban is an Associate Professor at the University of Pennsylvania and author of Why Everyone (Else) Is A Hypocrite. Follow him on Twitter: @rkurzban

Evolutionary Psychology & Embodied Cognition

Published 28 January, 2013

A recent paper published in the journal that hosts this blog, Evolutionary Psychology, explores an idea drawn from a set of ideas that travel under the label “embodied cognition.” Storey and Workman report some research in which subjects played a Prisoner’s Dilemma game while holding something hot (chemical hand-warmers) or cold (freezer packs). They predict and report that holding something warmer rather than colder leads to more cooperation because there is, in their words, “a link between real world temperature sensation and feelings of psychological warmth.”

The “link” is built on two ideas, and I apologize to the authors if I’m not rendering either or both properly. From what I can tell, the idea is that close relationships during development are literally “warm” because of the close physical contact involved with hugs and such. This history of feeling warm during such encounters causes a psychological association between literal warmth and close relationships. The second source of the “link” is neurophysiological, and the authors draw on findings that suggest that trusting someone leads to activation in the same brain area as one implicated in processing temperature.

The most important thing that strikes me about this application of the notion of “embodied cognition” from the standpoint of an evolutionary/functional analysis is that the proposal here is that, whatever the cause for the “link,” the effect of the link is to cause people to make mistakes. In the context of relationships – or decisions to cooperate or defect in an interaction – there are a number of cues that might reasonably be useful to attend to when making a decision. Is this a person I’ve known and will continue to interact with? What is the magnitude of the possible loss if I cooperate? Is there evidence that this person is disposed to like (dislike) me? These should, as normative and adaptive matters, be taken into account when making decisions about social interaction. If there is a long shadow of the future, for instance, then the expected value from subsequent interactions is greater.

In the reported work, subjects play ten rounds of a Prisoner’s Dilemma game, two blocks of five rounds holding either the hot or cold object, with the blocks counterbalanced. If I have understood the analysis correctly, the authors report that the payoff people earn is higher when the subjects in a PD pair are holding the hot object compared to the cold object. (My interest here is in the theory, not the stats, but it seems to me that the correct analysis is the frequency of Cooperate choices (a binary variable) by individuals rather than the payoff data to pairs, but it’s possible I misunderstood the analysis.)

In any case, to return to the theory, the temperature of what one is holding is a non sequitur. And I mean that in the literal, logical sense. The temperature of the room or the temperature of one’s hands is not any sort data on which such decision-making ought to be based, like choosing a mate because of their sign of the zodiac, or some other arbitrary, irrelevant property. Therefore, to the extent that temperature influences decisions, these decisions are being affected by irrelevant information, and are in error just to the extent that these effects are felt.

The ideas that motivate research of this type in the embodied cognition literature, then, rely on what strike me as a peculiar sort of byproduct. In the present case, the fact that two properties co-occur leading one to use the presence of one property when making decisions about the latter. There seems no obvious reason that noticing such co-occurrences ought to have such an effect. Further, the association seems to be particularly imperfect. People also get warm when they’re angry, possibly explaining why we have expressions such as hot under the collar. In Steven Brust’s novel, Five Hundred Years After, one character is explaining why he took care to be armed, saying:“Your Venerance, my master the Baroness gave me to understand the affair might become tolerably warm,” again illustrating how one might, from such constructions, have derived the reverse prediction.

More generally, it strikes me as just an odd sort of byproduct. Would it really have been that hard to engineer the trust system in such a way that it simply ignores the extraneous and irrelevant information about the temperature of one’s hands? Now, before the accusations of a commitment to “optimality” fly – lookin’ at you, Gary Marcus – of course there are any number of reasons that the mind might not be optimally designed. True enough. But as side effects go, this one seems particularly odd or, to put it another way, particularly easy to engineer out.

Further, it seems to me that there are just many facts about the world that don’t fit the notion. If being a little warmer makes you more trusting, should we find that our friends in the hot Philippines by and large are more trusting than our colder friends in Norway? It seems we should. But they’re not. By a far cry (see Fig. 1).

I might note that an additional source of motivation for the Storey and Workman paper is that it builds on prior results in this area, especially that of John Bargh and colleagues. I haven’t been following this work closely, but my sense is that there are at least some worries that the initial findings can be replicated. Again, I’m not an expert in this area, but it was a bit surprising to me that some concerns that have arisen in this area were not discussed by the authors.

The larger point is that most of the work of this type in embodied cognition, it seems to me, posits that the mind has the peculiar property of using a ton of irrelevant information in making decisions. Not only that, but there are any number of bits of irrelevant information the mind might use in making decisions. I myself have never really understood how one chooses which bits of irrelevant information are good candidates. Now, again, don’t get me wrong, I suspect that there are any number of cases in which the mind does indeed use irrelevant information – perhaps findings under the umbrella of the halo effect might be good exemplars. But information such as “heat” seems to me like an odd candidate for having an effect on social decision making.

  • discoveredjoys

    “The larger point is that most of the work of this type in embodied cognition, it seems to me, posits that the mind has the peculiar property of using a ton of irrelevant information in making decisions.”

    But is that an accurate statement? Or does embodied cognition posit that unconscious body/brain interactions ‘flavour’ the background state against which conscious decisions are made? In which case the ‘ton of irrelevant information’ is already reduced to a simpler feeling or emotion by the ordinary processes of the brain before rationality is engaged.

    I think this may be the case because of the evolutionary nature of the brain… animals with less powerful conscious ability would have still needed to interact with the external world effectively enough to live and produce offspring. A lioness, for instance, might have to resolve multiple streams of bodily information before ‘deciding’ without rational thought whether or not to hunt. Now while I can’t ‘know’ what all that information might be I can imagine that the state of the gut, blood sugar levels, bodily aches and pains, the hunger cries of cubs, thirst, seeing or smelling antelopes nearby, the distance to the antelopes, the state of the light, the weather, competition by other adults in the pride, the general level of conscious arousal, hormones in the blood, and so on. There is not a hunt/no hunt *decision* as such, but a hunt/no hunt behaviour as a consequence of the current states of the body.

    I suspect that our much vaunted human rationality is just an evolutionarily late addition to help refine the outcome of the embodied cognition.

    As far as the hot/cold hands idea goes it seems to me that warm hands/cold body could help produce (either a learned or an innate) sensation of comfort that a warm hands/warm body situation would not. A feeling of comfort could play into the summarised background state of the body which informs the conscious decisions. Perhaps further experimentation can tease this out. 

    People buy more food when they shop while hungry – embodied cognition suggests a reason. The effect of  warm hands doesn’t seem any stranger.

  • JaziZilber

    regarding replication worries on Bargh. 

    I followed only the priming of old age case which was most famous. 
    The “replicators” made two beginners mistakes. They made the subjects aware on their walking (studies on the unconscious seek lack of awareness), and did the priming stupidly (30 out of 30 words int he supposedly disguised priming word list. Without being a priming researcher, I knew that you never do it that way).So the most famous “failure to replicate” was a failure to do the experiment right. The replicators also REFUSED to redo the replication correctly (personal correspondence) 

  • Guest

    Seems to me that the warmth work has been done by many (not only Bargh). Plus, do scientists now base their evidence on blogs? In addition, where has the time gone that scientists read their classics (Harlow/Bowlby) and do a careful analysis of topics at hand (i.e., not mixing climate with holding a warm pack. These are not only based on different receptors, but also cognitively should have an enormous difference…)

  • Russell Jackson

    Fantastic post!  My own work utilizes embodied cognition and I find it frustrating to see interpretations of embodiment that are proposed to include irrelevant relationships.  I might add that that type of research can also feature demand characteristics at a seemingly higher rate than other research (e.g. tests of proximity using either chocolate or dog feces).  I feel that embodied cognition has led to otherwise unpredicted observations, but it is sometimes used in fanciful ways that fail to replicate.

  • http://profile.yahoo.com/NGK226MARR7UKAXBE7DBV6IF2Y Clara

    …a more parsimonious explanation might be that the temp S applied is more stressful to the subject than the cold S…relative to some condition-dependent threshold of stress, cooperation may be induced by the temp S…this suggestion is consistent w behavioral ecology theory & data where cooperation, & altruism, are likely to be “best of a bad job” Rs [see, for example, Austad’s work]…the present suggestion, also, requires no assumptions about conscious & aware processes…clara b. jones
    Twitter: http://twitter.com/cbjones1943
    Blog: http://vertebratesocialbehavior.blogspot.com

  • http://www.facebook.com/profile.php?id=1520826420 Mungo Park

    I could offer a different explanation – usually all environmental stimuli undergo appraisal and the brain will adjust the body functions to the environmental change. The peripheral blood flow is only one of theses things. The appraisal process itself  is encapsulated. This procedure is a basic in almost all emotion theories. The brain then perceives the bodily changes and reacts accordingly. “The hands are getting cold – something weird must be going on”

    This would explain an observation I made 20 years ago – that the higher the room temperature the more attractive a male rates a female – and in the presence of an attractive female male body temperature goes up and they start to perform weird undressing behaviors – the most interesting point is that the brain couples the temperature change to the situation itself and not the temperature stimulus.

  • Chuk

    Nice Brust reference.

  • Åse Innes-Ker

    Mungo Park’s explanation is much what I came upon with my mulling. The mechanism would be some noticing of shifts in the body – in this case the temperature (blood-flow) to the hands.  Emotion researchers have spent a long time doing these kinds of bodily manipulations exploring how the body feeds back into the feeling/emotion system, showing it is kind of bi-directional.  Ekman did this early (evidently when they did their AU’s they noticed that people got snappy when they were pulling down their foreheads – which lead to a series of studies). Strack stuck pencils in peoples mouths and got them to think cartoons were funnier (or they did sloppier rating because it is tricky to swallow).  Niedenthal found that sticking the pens in the mouth disrupted emotion recognition (and, even I did that, as the lowly last grad student author). Botox disrupts recogniton of negative emotions. You can feel a shift from hunching to straightening up your back (I demonstrate this frequently in my course – and it is obvious). Clearly none of the body manipulations are strong enough to overcome the kind of standard sources of the emotions, but they sure can modulate them.  Or, something I read on Eric Charles blog fixing psychology (A review of Johnson-Laird If I recall), there are lots of things that are kind of… bidirectional. You gaze into your beloved eyes, but you can start feeling romantic towards someone by just staring into their eyes. You smile when you are happy, but pulling up the corners of the mouth can give you a faint feel of that emotion. (Of course, telling someone to “smile” may result in a slug – at least I felt like doing that when that happened to me). It won’t cure depression (I think Zajonc said that, if I recall right), but it will shift things.

    Still, I frequently feel kinda iffy about the supposedly embodied pieces. But, the ones connecting to emotion, emotional processes, and physiological processes I buy, because that has been worked on for a few decades by now.  (Or, I’m just being tribal, as that is my research family).

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