The cover illustration for the story “Dating in a Digital World,” by Eli J. Finkel, Paul W. Eastwick, Benjamin R. Karney, Harry T. Reis and Susan Sprecher, places the two people in perfect position for the function of the vomeronasal organ. This tiny structure hides about one centimeter inside the nose in each nostril along the middle wall, where it can sample each inhalation for pheromones. Mating involves exchanging pheromones, which provide information used by the brain outside of conscious thought.
Until we develop some technique to transfer pheromone information via the computer screen, we will be at a loss to complete the biological process that initiates the mating protocol for our species.
Hidden Hills, Calif.
Editors' note: For more information on the vomeronasal organ, see “Sex and the Secret Nerve,” by R. Douglas Fields; Scientific American Mind, February/March 2007.
IS INTELLIGENCE FIXED?
In “Building Better Brains,” John Jonides, Susanne M. Jaeggi, Martin Buschkuehl and Priti Shah summarize findings that they interpret to indicate that “fluid” intelligence—the ability to solve novel problems and adapt to new situations—can be increased to a statistically and practically significant degree through working memory training.
The scientific jury is still very much out on whether working memory training truly increases fluid intelligence. With our colleagues, two of us (Hambrick and Redick) recently published a failure to replicate the authors' widely cited 2008 finding, which they describe in “Building Better Brains,” that working memory training increases fluid intelligence in young adults. A report of our study appeared online in June in the Journal of Experimental Psychology: General.
In a study in Developmental Psychology in May, a meta-analysis of the quantitative findings of 23 studies on working memory training—including studies by Jonides et al.—researchers Monica Melby-Lervåg and Charles Hulme found no convincing evidence that working memory training improves either adults' or children's fluid intelligence or scholastic outcomes.
It may turn out that working memory training has generalizable benefits for only some people, under only some circumstances, but it is far too soon to tell even that much. In the meantime, scientists should avoid portraying evidence for the efficacy of working memory training as more definitive than it is.
David Z. Hambrick
Michigan State University
Frederick L. Oswald
Thomas S. Redick
Indiana University–Purdue University Columbus
THE AUTHORS RESPOND: Hambrick and his colleagues' failure to replicate our findings must be taken in the context of research from at least three other independent laboratories that have successfully replicated our original work. As we pointed out in our article, inconsistent results across studies do not necessarily mean that the original finding is false but instead can provide a valuable opportunity to learn more about the underlying phenomenon.
The study procedure used by Hambrick et al. has several notable weaknesses. For instance, the time to administer each of the 17 tests was so short that measurement quality was probably somewhat questionable. Participants got the best score possible on some of the pretests, thereby giving them no opportunity to improve as a function of cognitive training. Finally, the training curves of their participants were notably shallower than those of ours, and we have shown in published research that transfer is related to how well people train. Although we value failures to replicate that are scientifically sound, we have reason to doubt that the cited paper is one of these.