magazine issue 4 2014 / Issue 20

Manipulating the body, measuring the body, and tinkering in the name of Psychology

• written by Thomas Schubert
• edited by Spike Lee

New scientific approaches often rise with the availability of new methods, and can stall when those methods do not evolve further. New methods can be particularly influential if they allow a wide range of application without demanding a lot of resources. In the hands of creative graduate students, such methods can quickly turn into productive tools. The field of embodiment, the topic of this special issue, is no difference. In this text, I trace one development that has contributed a lot to the current state of the field: manipulating the body to influence thought. I then outline another one that may take it beyond its current level: measuring how thought influences the body.

Embodiment

Embodiment refers to an idea that has excited many psychologists in the past years. The idea of embodiment is that the way our mind works is deeply rooted in the way our body works. In particular, one of the ideas discussed by researchers in this field is that the ideas we hold about the world – our mental toolbox to understand the world, to categorize it, and to provide it with labels – is based on the way our body interacts with the environment. What do they mean by that?

For some concepts, this is obvious. Take colours as an example. Our colour concepts develop from the interaction of the cones in our retina with light of different wave lengths entering the eye. The three different types of cones respond to three different wave lengths. From these differences, our brain and mind construct the colours red, blue, green, and every other colour. These colours do not actually exist in the world – light consists only of different wave lengths. Colours are entirely the product of how our retina and brain interact with the world. If we had different cones, or a different number of cones, we would see different colours. So, here our brain creates embodied concepts in the first place. It is fun thinking about the consequences (the Radiolab Podcast has a great discussion of this [http://www.radiolab.org/2012/may/21/]).

In other areas the embodiment claim idea is more controversial. For instance, when we judge the importance of a book, we are supposed not to judge it by its cover, but to ponder the knowledge that is written down in it, the beauty of its language, and to compare its wisdom and impact to those of other books. Importance sure sounds abstract and intangible – it is a different kind of concept than colour, right? However, that does not seem to be the way our mind works.

Instead, the embodiment approach argues, even seemingly abstract concepts like importance are rooted in bodily experience. The reason is that in order to understand abstract concepts, we connect them to more concrete experiences. We ground cognition in the body (Barsalou, 2008; Lakoff & Johnson, 1980). Often, metaphors give away the groundings we construct. For importance, one of the crucial sensory dimensions seems to be weight. Embodiment researchers love to scour metaphors to track down those sensory dimensions, and indeed it is easy to find metaphors that connect importance to weigh.

Manipulating the body and measuring thought

But how can psychological research test such ideas in experiments? The main path that has been taken in the last years is to conduct experiments in which the sensory dimension of interest is manipulated in a subtle way. I call this the manipulate-the-body strategy. To show the embodiment of importance, this was done by changing the weight of an object that the participants of these studies held in their hands. For instance, participants filled in a questionnaire holding either a light or a heavy clipboard (Ackerman, Nocera, & Bargh, 2010; Jostmann, Lakens, & Schubert, 2009; Maglio & Trope, 2012). Or, participants held a book that was either light, or made heavier with a concealed weight (Chandler, Reinhard, & Schwarz, 2012). Participants had to perform judgments that involved importance – for instance judging the importance of the book – while holding these objects. And voilà, those who held the heavier object assigned on average more importance than those who held the lighter object. (Note: There is an ongoing and healthy debate about whether this effect is robust. Consult the webpage of Daniël Lakens [https://sites.google.com/site/lakens2/publications] for a list of replication attempts.)

The manipulate-the-body strategy has been used in many studies that investigated the embodiment approach. Let us look at three examples.

Approach and avoidance are embodied in arm movements: We avoid coming close to things we do not like, and we approach things we like. Often we do this by extending our arm to push something away, or flexing our arm to pull something towards us. The idea of valence is thus grounded in approach and avoidance movements. The manipulating-the-body strategy has been applied to study this. For instance, in experiments, participants are instructed to push against a bar, or to pull it towards them. Extending an arm leads to less favourable ratings of objects encountered at the same time than flexing an arm (Cacioppo, Priester, & Berntson, 1993).