Social Signals

Be honest

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Science  17 Nov 2017:
Vol. 358, Issue 6365, pp. 883-884
DOI: 10.1126/science.358.6365.883-c

Fake signals of aggression are policed and punished among fish.

PHOTO: BLICKWINKEL/ALAMY STOCK PHOTO

Signals of quality and intent are common among animals, but there is much debate about how the honesty of these signals is maintained. Generally, it has been concluded that honesty in the signaling of quality is inherent—for example, the production of color can be costly, so bright colors must honestly signal a healthy and high-quality individual. Signals of intent, however, are more easily bluffed. Bachman et al. used manipulation experiments to test the honesty of facial signaling in Princess of Burundi cichlids and whether it was enforced. A single, dynamically controlled black color bar on the face of both males and females honestly signaled aggressive intent in these fish. However, when the stripe was manipulated by experimenters, “dishonest” fish were punished with a greater number of attacks than were control fish. Thus, social policing maintained the honesty of signaling, even though the signal itself is dynamic and easily changed. Such social maintenance of honesty may act as a selective force on dynamic signals.

Evol. Lett. 10.1002/evl3.24 (2017).

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