The　hormones　oxytocin,　vasopressin,　and　testosterone　have　been　implicated　in　cooperative　behaviours　and　have　attracted　increasing　research　interest　for　their　potential　to　regulate　human　cooperation　in　both　healthy　and　clinical　populations.　However,　the　behavioural　effects　of　the　administration　of　these　hormones　remain　to　be　verified.　The　current　analysis　included　41　studies　involving　3,269　participants　with　a　narrow　age　range.　We　examined　the　administration　effects　of　these　hormones　on　cooperative　behaviour　and　the　regulatory　effects　of　individual　characteristics,　hormone　interventions,　and　task　structure　and　context.　Results　revealed　a　moderate　positive　effect　size　of　oxytocin　intranasal　administration,　a　large　negative　effect　size　of　vasopressin　intranasal　administration,　and　nonsignificant　effects　of　testosterone　administration　on　cooperative　behaviours.　Participants　with　mental　dysfunctions　were　less　sensitive　to　oxytocin　and　vasopressin　administration.　Oxytocin　administra-tion　was　effective　in　an　in-group　situation　and　for　initial　choices,　corroborating　a　Tit-for-Tat　strategy.