Differential outcomes of unilateral interferences at birth De Boyer des Roches, A. Durier, V. Richard-Yris, M.-A. Blois-Heulin, C. Ezzaouïa, M. Hausberger, M. Henry, S. behaviour early experience side bias foals Behavioural modifications, including modifications of emotional reactivity, can occur following early experience such as handling (manual rubbing). Here, we investigated the effects of unilateral tactile stimulation at an early stage on emotional reactions later on. We handled newborn foals intensively on one side of their body. This early unilateral tactile experience had medium-term effects: the reactions of foals to a human approach, when they were 10 days old, differed according to the side stimulated at birth. Fewer right-handled foals accepted contact with humans, they delayed first contact longer and they evaded approaching humans sooner than did non-handled and lefthandled foals. These results raise questions concerning the organization of neonatal care in animals and humans. The Royal Society EthoS, UMR 6552 CNRS Université de Rennes 1 2011 Article scientifique Biology Letters, 2011, 7, 177-180 https://ecm.univ-rennes1.fr/nuxeo/site/esupversions/fb99f328-b27f-4fe3-b1ae-5b1a26e7ecd9 doi:10.1098/rsbl.2010.0979 Blanc, N. (2011). Toucher, émotion : quels impacts ont les manipulations à la naissance ? Science Ouest, n° 283, pp. 8-9 Bordes, I. (2011). Poulains et bébés au coeur d'une même étude. Ouest France, 18 janvier, p. 6