title: Spontaneous prosocial choice by captive bottlenose dolphins, Tursiops truncatus.
abstract: Dolphins exhibit prosocial behavior across several different contexts. However, only a few experimental studies have investigated the psychological mechanisms underlying this behavior. In this study, we investigated the mechanisms underlying prosociality in bottlenose dolphins (Tursiops truncatus). In the experiments, water shower devices, developed as environmental enrichment items, were used. Two paradigms were used to measure prosociality. The first was the prosocial choice task, involving the subject typically being offered one choice between two options. The first option provided a reward (take a shower) to both the subject and partner (prosocial choice). The second option provided a reward only to the subject (selfish choice). The second paradigm was the giving assistance task, involving the subject being provided a choice between providing instrumental help to the partner (prosocial choice) or doing nothing. It was observed that the subjects chose the prosocial choices in both paradigms. In these experiments, prosocial choices were spontaneously taken without requests from the partners. These results indicated that the dolphins show preference for other-regarding behavior.
authors.affiliation: Tokiwa University, Mito, Ibaraki, 310-8585, Japan. Electronic address: fnakahar@tokiwa.ac.jp.
authors.forename: Fumio
authors.initials: F
authors.lastname: Nakahara
authors.affiliation: Kujukushima Aquarium-Umi Kirara, Sasebo, Nagasaki, 858-0922, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Komaba
authors.affiliation: Kujukushima Aquarium-Umi Kirara, Sasebo, Nagasaki, 858-0922, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Sato
authors.affiliation: Kujukushima Aquarium-Umi Kirara, Sasebo, Nagasaki, 858-0922, Japan.
authors.forename: Hisako
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Kujukushima Aquarium-Umi Kirara, Sasebo, Nagasaki, 858-0922, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Komaba
authors.affiliation: Kujukushima Aquarium-Umi Kirara, Sasebo, Nagasaki, 858-0922, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kawakubo
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D050681:Bottle-Nosed Dolphin / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D003299:Cooperative Behavior; D005260:Female
keywords: Bottlenose dolphin; Cooperative behavior; Other-regarding preferences; Proactive prosociality; Prosocial behavior