 Knowing that if A>B and B>C, then A>C, is another type of evidence for intelligence, and it can be applied in the context of dominance hierarchies.In a study with the cichlid "Astatotilapia burtoni", eight observer fish could watch individual A beat individual B, then B over C, C over D, and D over E. The observer fish were then given a choice of associating with either B or D (both of which they had seen win once and lose once).All eight observer fish spent more time next to D. Fish in this species prefer to associate with more dominant individuals, so the preference for D showed that the observers had worked out that B was superior to C, and C to D, and therefore D was dominant to B.