Spite: Hamilton’s unproven theory

1) Laboratory of Apiculture and Social Insects, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK * Current address: Department of Ecology and Evolutionary Biology, Rice University, MS 170, 6100 Main, Houston, Texas 77005, USA (e-mail: [email protected]) 2) Laboratory of Entomology, Zoological Institute, Katholieke Universiteit Leuven, Naamsestraat 59, B-3000 Leuven, Belgium 3) Laboratory of Apiculture and Social Insects, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK