From fish to fashion: experimental and theoretical insights into the evolution of culture

Abstract

Recent years have witnessed a re-evaluation of the cognitive capabilities of fishes, including with respect to social learning. Indeed, some of the best experimental evidence for animal traditions can be found in fishes. Laboratory experimental studies reveal that many fishes acquire dietary, food site and mating preferences, predator recognition and avoidance behaviour, and learn pathways, through copying other fishes. Concentrating on foraging behaviour, we will present the findings of laboratory experiments that reveal social learning, behavioural innovation, the diffusion of novel behaviour through populations and traditional use of food sites. Further studies reveal surprisingly complex social learning strategies deployed by sticklebacks. We will go on to place these observations of fish in a phylogenetic context, describing in which respects the learning and traditionality of fish are similar to, and differ from, that observed in other animals. We end by drawing on theoretical insights to suggest processes that may have played important roles in the evolution of the human cultural capability.

Figure 1.

(a) The proportion (mean ± s.e.) of trials in which observer guppies tested singly took the green hole to a food source, given that their demonstrators were trained to take the green (circle) or red (square) hole, and that they had one, three or five demonstrators. (b) The proportion of trials in which subjects took the green hole to a food source, in transmission chains where founder populations were trained to take the green (circle) or red (square) hole. Each point represents the mean of the pooled performances of the fish in each group. (c) Mean (± s.e.) preference for the personal-poor feeder (time spent near the personal-poor feeder minus time spent near the personal-rich feeder from instantaneous sampling every 6 s for 90 s) in the personal-information only condition (‘control’, white bar), the social-information only conditions (black bars, where 3–3 denotes three fish shoaling at one feeder and three fish at the other feeder) and the public-information conditions (hashed bars, where 3P–3R denotes three fish feeding at the public-poor feeder and three fish at the public-rich feeder, respectively). See text for full details. Asterisks above bars indicate a significant difference from the control group; horizontal lines indicate orthogonal pairwise comparisons between groups. *p < 0.05, **p < 0.01 and ***p < 0.001. (d) Mean (± s.e.) standard error difference (personal-poor minus personal-rich) in the number of instances that the fish was present in the ‘goal zone’ around each feeder (from instantaneous sampling of the fish's location every 6 s for the first 90 s following the start of the choice test), in fish trained on a 6|2 (i.e. 6 and 2 deliveries to rich and poor feeders, respectively; black bars) or 8|4 (hashed bars) regime and subsequently exposed to either a 2|6 or a 4|8 public demonstration (denoted as ‘2|6’ or ‘4|8’, respectively). Controls received no public demonstration (see text for full details). Asterisks denote either a significant difference from zero (in controls) or a significant difference between groups: ***p < 0.001, *p < 0.05. (Reproduced with permission from [9] (a,b), [11] (c) and [12] (d).)