competition and the N-effect 

 I've taken my fair share of standardized tests, so I sat up and took notice of a recent  study  published in  Psychological Science  about what happens to SAT scores when students take the test in crowded versus empty rooms. What the two researchers, Stephen Garica (UMich) and Avishalom Tor (Haifa University), are out to study is the impact that increased competition can have on one's performance. The results of this line of research are pretty interesting. 


 Here's how they did it. First, Garcia & Tor  took state-by-state mean SAT scores as their outcome of interest. (This unfortunately restricts their analysis to an  n  of 50, somewhat ironic in an article about the "N effect.") Second, to measure "competition," Garcia & Tor created a "density" variable by dividing the number of test-takers by the number of state testing venues. This, they contend, captures the likelihood that a student would be sitting in a jam-packed classroom (teeming with potential competitors) or in a relatively empty competition-free environment. Third, Garcia & Tor controlled for a host of potential confounders, among these state funding for elementary and secondary education, per capita income, population density, the percent of students taking the SAT, the percent of test-takers reporting having a college-educated parent, and the percent of test-takers self-identifying as a racial minority. 

 The results suggest that the denser a test-taking environment is, the lower the state mean SAT scores are. This, the authors contend, is evidence in favor of the idea that as the number of potential competitors increases, one's motivation to compete dwindles.  

 I'm actually not 100% convinced that the two researchers have controlled for all possible confounding variables. Teacher quality, student-to-teacher ratios, strength of parental involvement, spending per student -- to name just a few -- could be factors that would affect both the probability of treatment (density of the venue) as well as the potential outcome (SAT scores). In addition, the coarseness of the measurements (which are all at the state level) makes it impossible to include confounders and other interesting variables at the city or student level. For example you would think that ambitious parents might encourage their children to take exams in a more comfortable (more rural) setting; this parental ambition would also in turn translate into higher SAT scores. When you measure things at the state level, however, you make it difficult to examine things like this. 

 The  Psychological Sciences  paper is actually more of a compendium of studies undertaken by Garcia & Tor on the topic. Other studies are more persuasive. For example, the authors administered a timed online test to a group of Michigan undergraduates. A subset of the group were told that they were competing against ten other students and that the quickest and most accurate 20% would get a $5 prize. The other subset were told that they were competing against 100 students and that, similarly, the quickest and most accurate 20% would get a $5 prize. What happened? The group competing against 10 students finished the online test faster than the other group (although note that there was no difference in the accuracy of the two groups). 

 This whole N-effect is interesting to think about -- are we more likely to sell ourselves short when it appears that we're facing stiff competition? In my experience, this seems true. (Although, under this rationale, my own best performance would have been on the GRE, where I sat alone at a computer while taking the test; sufficed to say, it wasn't a very strong showing.)  

 I'd also be interested in how this line of research contradicts or complements the social networks type of research being conducted by James Fowler,  Nicholas Christakis, and the like. I am guessing here, but those folks would maybe counter that it's not competition that makes people perform more poorly -- rather, one might think that it's the camaraderie of being in a small group (a "we're-all-in-this-together" kind of attitude) that could positively influence people working in more intimate environments. 

 I imagine that others have more experience with this kind of research, and I would be interested in hearing thoughts on this.