<Table> <Tr> <Td> Part of a series on </Td> </Tr> <Tr> <Th> Homicide </Th> </Tr> <Tr> <Th> Murder </Th> </Tr> <Tr> <Td> <P> Note: Varies by jurisdiction </P> <Ul> <Li> Assassination </Li> <Li> Cannibalism </Li> <Li> Child murder </Li> <Li> Consensual homicide </Li> <Li> Contract killing </Li> <Li> Crime of passion </Li> <Li> Depraved - heart murder </Li> <Li> Execution - style murder </Li> <Li> Felony murder rule </Li> <Li> Feticide </Li> <Li> Honor killing </Li> <Li> Human sacrifice <Ul> <Li> Child sacrifice </Li> </Ul> </Li> <Li> Infanticide </Li> <Li> Lust murder </Li> <Li> Lynching </Li> <Li> Mass murder </Li> <Li> Mass shooting </Li> <Li> Misdemeanor murder </Li> <Li> Murder--suicide </Li> <Li> Poisoning </Li> <Li> Proxy murder </Li> <Li> Pseudocommando </Li> <Li> Lonely hearts killer </Li> <Li> Serial killer </Li> <Li> Spree killer </Li> <Li> Thrill killing </Li> <Li> Torture murder </Li> <Li> Vehicle - ramming attack </Li> <Li> Internet homicide </Li> </Ul> </Td> </Tr> <Tr> <Th> Manslaughter </Th> </Tr> <Tr> <Td> <Ul> <Li> In English law </Li> <Li> Negligent homicide </Li> <Li> Vehicular homicide </Li> </Ul> </Td> </Tr> <Tr> <Th> Non-criminal homicide </Th> </Tr> <Tr> <Td> <P> Note: Varies by jurisdiction </P> <Ul> <Li> Euthanasia </Li> <Li> Assisted suicide </Li> <Li> Capital punishment </Li> <Li> Feticide </Li> <Li> Justifiable homicide </Li> <Li> War </Li> </Ul> </Td> </Tr> <Tr> <Th> By victim or victims </Th> </Tr> <Tr> <Td> <Ul> <Li> Suicide </Li> </Ul> </Td> </Tr> <Tr> <Th> Family </Th> </Tr> <Tr> <Td> <Ul> <Li> Familicide </Li> <Li> Avunculicide (Nepoticide) </Li> <Li> Prolicide <Ul> <Li> Filicide </Li> <Li> Infanticide </Li> <Li> Neonaticide </Li> </Ul> </Li> <Li> Siblicide <Ul> <Li> Fratricide </Li> <Li> Sororicide </Li> </Ul> </Li> <Li> Mariticide </Li> <Li> Uxoricide </Li> <Li> Parricide <Ul> <Li> Matricide </Li> <Li> Patricide </Li> </Ul> </Li> </Ul> </Td> </Tr> <Tr> <Th> Other </Th> </Tr> <Tr> <Td> <Ul> <Li> Blood libel </Li> <Li> Capital punishment </Li> <Li> Crucifixion </Li> <Li> Stoning </Li> <Li> Democide </Li> <Li> Friendly fire </Li> <Li> Genocide </Li> <Li> Gendercide </Li> <Li> Omnicide </Li> <Li> Regicide </Li> <Li> Tyrannicide </Li> <Li> War crime </Li> </Ul> </Td> </Tr> <Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> </Table> <Tr> <Td> Part of a series on </Td> </Tr> <Tr> <Th> Homicide </Th> </Tr>

What was most often the primary catalyst in underwood's study of siblicide