I wish to clarify your perspective on David Shanks's failure to replicate our 'intelligence priming' results (see Nature 497, 16; 2013; and clarification at go.nature.com/8ep3nc).

Variations and extensions of the effect of intelligence- or stupidity-related primes on intellectual performance have been widely studied since we published our original paper (A. Dijksterhuis and A. van Knippenberg J. Pers. Soc. Psychol. 74, 865–877; 1998). These so far amount to 27 independent experiments from 12 different labs in eight countries (for instance, see A. D. Galinsky et al. J. Pers. Soc. Psychol. 95, 404–419; 2008; further references available from the author). To my knowledge, Shanks et al. are the first to publish a failure to replicate our findings (although see also www.psychfiledrawer.org, which lists two single-study unsuccessful replication attempts and one successful attempt).

Given that the percentage of successful replications in psychology is low (it seems to be 30–40%), there is no reason to assume that the intelligence-priming effect is especially difficult to reproduce. Also, since 1998 we have gained a better understanding of the mechanism underlying the priming effect (see, for example, S. L. Bengtsson et al. Soc. Cogn. Affect. Neurosci. 6, 417–425; 2011).

There are technical and methodological factors in the experimental design used by Shanks and his team that could explain their inability to replicate our results (details available from the author). For example, their general-knowledge questionnaire was unusually difficult and might have itself moderated the effect — an idea that awaits further research.