To appear in Trends in Cognitive Sciences, January 2006 Evidence for infants’ understanding of false beliefs should not be dismissed Response to Ruffman and Perner Gergely Csibra and Victoria Southgate School of Psychology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK In their response to Leslie [1], Ruffman & Perner (R&P) reiterate their position that there is no need to explain Onishi & Baillargeon’s (O&B) recent findings [2] with 15-month-olds in terms of attributing false beliefs (FB). Here we put forward three reasons why their points do not explain the infants’ performance. (1) We are not surprised that Leslie [3] did not respond to Perner & Ruffman’s "neurological" argument [4], according to which "cells in the brain code for configurations of persons relating to objects". To support their argument, they cited (i) a neural network model [5] which hypothesized rather than demonstrated the forming of associations in the prefrontal cortex between two rather than three stimulus features; and (ii) a neurophysiological study [6] showing that cells in the rat's hippocampal region are activated differently for novel and familiar arrangements of pictures, without demonstrating that those cells coded for episodes rather than familiarity of arrangements per se. Although these studies suggest that brains could form such associations, to present them as evidence for 15-month-olds forming the particular episodic three-way associations that Perner & Ruffman's account requires is unconvincing. (2) Although we certainly agree with R&P that teleological understanding [7] could account for many examples of early competence demonstrated in infants, this is a red herring in this debate. The teleological model can only take into account actual states of reality, and is therefore unable to explain O&B’s result. In fact, Gergely & Csibra [7] explicitly stated that as soon as the teleological interpretation is applied to fictional states (as required by this result), it has been upgraded to mentalistic understanding. (3) R&P ask why infants would not default to answering in terms of reality on O&B’s task if, as Leslie suggests, this is what children failing the traditional FB task do. The answer to this question is simple: in the looking version of the FB task [2], infants are not responding to any question. R&P argue that as two-year-olds respond correctly to an ‘I wonder where...’ prompt in object search situations, they should also respond correctly to that prompt in the FB task, if indeed they have a concept of FB. Although R&P couch the requirements of these two different tasks as equivalent, this is not the case. In the object search task, the correct response to the ‘where’ question is the actual location of the object, whereas in the implict FB task [8] it is the location without the object. It is plausible that younger two-year-olds may prematurely interpret a 'where' question as referring to the hidden object, which would result in a correct anticipatory response in the object search task and an incorrect response in the FB task. The main advantage of O&B’s paradigm is that it is devoid of these pragmatic difficulties. It is an open question whether two-year-olds, who fail both the explicit and implicit false belief tasks, would pass a similar test that does not involve interpreting or answering adults' questions. References 1. Ruffman, T. and Perner. J. (2005). Do infants really understand false belief? Response to Leslie. Trends Cogn. Sci. 9, 462-463. 2. Onishi, K. and Baillargeon, R. (2005). Do 15-month-old infants understand false beliefs? Science 308, 255-258. 3. Leslie, A. M. (2005). Developmental parallels in understanding minds and bodies. Trends Cogn. Sci. 9, 459-462. 4. Perner, J. and Ruffman, T. (2005). Infants' insight into the mind: How deep? Science 308, 214-216. 5. Morton, J. B. and Munakata, Y. (2002). Active versus latent representations: A neural network model of perseveration, dissociation, and decalage. Dev. Psychobiol. 40, 255-265. 6. Wan, H. et al. (1999). Different contributions of the hippocampus and perirhinal cortex to recognition memory. J. Neurosci. 19, 1142-1148. 7. Gergely, G. and Csibra, G. (2003). Teleological reasoning in infancy: The naïve theory of rational action. Trends Cogn. Sci. 7, 287-292. 8. Clements, W. A. and Perner, J. (1994). Implicit understanding of belief. Cogn. Dev. 9, 377-395. Corresponding author: G. Csibra (g.csibra@bbk.ac.uk).