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

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).

Number size is embodied on a spatial dimension from left to right: Because we write from left to right, we come to associate “become more” or “later” or “larger”, and also “impact” and “agency” with the movement towards the right. Among people who learn to write from right to left (e.g., Hebrew, Arabic, Urdu), this is reversed! Again, the manipulate-the-body strategy works: When participants from left-to-right cultures are induced to lean to the right, they estimate buildings to be larger than when they are induced to lean to the left (Eerland, Guadalupe, & Zwaan, 2011).

Power is embodied in certain postures and gestures: When participants are put into a typical “power pose” (think Superman), or to make a gesture associated with winning (e.g. raising a fist), they feel more powerful (Carney, Cuddy, & Yap, 2010; Schubert & Koole, 2009). (Watch the TED talk by Amy Cuddy [http://on.ted.com/Cuddy] for more details.).

Experiments of this style are often easy to conduct – they require single participant experimentation, but no complicated equipment or measures (the study from Eerland et al., 2011 cited above is an exception, it used a Wii balance board to trick participants into leaning to the side). Indeed, the simplicity of combining an embodied manipulation with a questionnaire is part of the charm of these experiments. Consequently, many more such studies exist (see Barsalou, 2008; Glenberg, 2010; Landau, Meier, & Keefer, 2010; Landau, Robinson, & Meier, 2013).

Despite their elegance, these studies also have a problem: They tend to be open for alternative explanations. In particular, even when experimenters make the manipulation unobtrusive, it might happen that the participants spontaneously and consciously judge the sensations they experience, such as “wow, this book is really heavy”. The experimenters typically debrief carefully to check for such spontaneous judgments, but it is possible that we sometimes miss them. It might not sound like a big deal, but if participants do explicitly think about the manipulated sensation, this creates a problem for the interpretation of the studies. The problem is that they can then be explained by other processes than embodied concepts – for instance by judgments based on general knowledge about the world. As a result, the embodiment research has a problem: It has an easy way to come up with elegant studies, but their interpretation is sometimes difficult.