title: Target animacy influences gorilla handedness.
abstract: We investigated the unimanual actions of a biological family group of twelve western lowland gorillas (Gorilla gorilla gorilla) using a methodological approach designed to assess behavior within social context from a bottom-up perspective. Measures of both the lateralization of unimanual actions (left, right) and the target of the action (animate, inanimate) were assessed during dual, synchronized video observations of naturalistic behavior. This paper demonstrates a corelationship between handedness and the animate quality of the target object. Analyses demonstrated a significant interaction between lateralized unimanual actions and target animacy and a right-hand bias for actions directed toward inanimate targets. We suggest that lateralized motor preference reflects the different processing capabilities of the left and right hemispheres, as influenced by the emotive (animate) and/or functional (inanimate) characteristics of the target, respectively.
authors.affiliation: Department of Psychology, University of Westminster, 309 Regent Street, London W1B 2UW, UK. g.forrester@westminster.ac.uk
authors.forename: Gillian S
authors.initials: GS
authors.lastname: Forrester
authors.forename: David A
authors.initials: DA
authors.lastname: Leavens
authors.forename: Caterina
authors.initials: C
authors.lastname: Quaresmini
authors.forename: Giorgio
authors.initials: G
authors.lastname: Vallortigara
mesh_terms: D000819:Animal Communication; D000818:Animals; D005260:Female; D007839:Functional Laterality; D006071:Gorilla gorilla / Q000523:psychology*; D008297:Male