Anim Cogn (2008) 11:139–146 DOI 10.1007/s10071-007-0099-y 123 ORIGINAL PAPER Is there an innate geometric module? EVects of experience with angular geometric cues on spatial re-orientation based on the shape of the environment Cinzia Chiandetti · Giorgio Vallortigara Received: 2 April 2007 / Revised: 13 June 2007 / Accepted: 23 June 2007 / Published online: 13 July 2007  Springer-Verlag 2007 Abstract Non-human animals and human children can make use of the geometric shape of an environment for spa- tial reorientation and in some circumstances reliance on purely geometric information (metric properties of surfaces and sense) can overcome the use of local featural cues. Lit- tle is known as to whether the use of geometric information is in some way reliant on past experience or, as would likely be argued by advocates of the notion of a geometric module, it is innate. We tested the navigational abilities of newborn domestic chicks reared in either rectangular or cir- cular cages. Chicks were trained in a rectangular-shaped enclosure with panels placed at the corners to provide salient featural cues. Rectangular-reared and circular-reared chicks proved equally able to learn the task. When tested after removal of the featural cues, both rectangular- and cir- cular-reared chicks showed evidence that they had sponta- neously encoded geometric information. Moreover, when trained in a rectangular-shaped enclosure without any fea- tural cues, chicks reared in rectangular-, circular-, or c- shaped cages proved to be equally able to learn and perform the task using geometric information. These results suggest that eVective use of geometric information for spatial reori- entation does not require experience in environments with right angles and metrically distinct surfaces, thus support- ing the hypothesis of a predisposed geometric module in the animal brain. Keywords Geometric module · Spatial orientation · Modularity · Chicks · Children Introduction When disoriented in a rectangular enclosure several verte- brate species (reviews in Cheng and Newcombe 2005; Spelke 2003; Vallortigara 2006) appear to make use of the shape of the enclosure to reorient themselves, relying on metric information (long wall versus short wall) and direc- tional sense (left versus right). Several species have also proved able to conjoin geometric information (the shape of the enclosure) with non-geometric information (e.g. the colour of a wall) in order to reorient themselves [e.g. Wsh: redtail splitWns (Xenotoca eiseni): Sovrano et al. 2002, 2003; goldWsh (Carassius auratus): Vargas et al. 2004; birds: chicks (Gallus gallus): Vallortigara et al. 1990, 2004; pigeons (Columba livia): Kelly et al. 1998; Vargas et al. 2004a; mammals: rhesus monkeys: Gouteux et al. 2001; tamarins: Deipolyi et al. 2001]. Interestingly, however, a “primacy” of geometric information seems to be apparent in spatial reorientation. When animals are trained in the presence of conspicuous local, non-geometric cues, such as panels located at the corners of a rectangular enclosure, and subsequently tested after removal of these featural cues, their behaviour usually reveals that spontaneous encoding of geometric information has occurred, in spite of the fact that featural information alone suYced for spatial reorienta- tion during training (chicks: Vallortigara et al. 1990; pigeons: Kelly et al. 1998; Wsh: Sovrano et al. 2003). The original claims by Cheng (1986) and Hermer and Spelke (1994, 1996) for the existence of an encapsulated geometric module, sensu Fodor (1983), have been tempered in recent years by evidence that conjoining geometric and C. Chiandetti (&) · G. Vallortigara Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, Via S. Anastasio 12, 34134 Trieste, Italy e-mail: cchiandetti@univ.trieste.it URL: http://www.psico.univ.trieste.it/labs/acn-lab/ G. Vallortigara e-mail: vallorti@univ.trieste.it