Figure 6.

Receivers’ accuracy by rounds and by the nine treatments. Left-hand column: no trade-off manipulations, middle-colum: trade-off manipulations, right-hand column: conditional trade-off manipulations. Upper row: negative signal cost for high-quality signallers, middle row: cost-free for high-quality signallers, bottom row: positive signal cost for high-quality signallers. ‘Receiver accuracy’ panels: dark blue and orange/red lines show the proportion of high- and low-quality signallers receiving the resource respectively. At the honest equilibrium, receivers can find out the quality of the signaller from the signal, thus they should donate the resource only to high-quality signallers and never to low-quality ones (dark blue at 1; orange/red at zero). Dots show the average per round, overlay shows one standard deviation.