Table 1.

Treatment conditions. (The table shows the costs low- and high-quality signallers have to pay (in HUF) for using low-intensity or high-intensity signals (c_LL for low-intensity signal, c_LH for high-intensity signal for a low-quality signaller, c_HL for low-intensity signal, c_HH for high-intensity signal for a high-quality signaller). Costs are indicated with positive numbers. Negative numbers indicate negative costs (i.e. positive rewards for choosing the given signal). First, treatments differed in whether the use of the high-intensity signal is costly, cost-free, or profitable for high-quality signallers. Second, treatments also differed in whether there was no trade-off between sending the low-intensity and high-intensity signal (c_LH−c_LL = c_HH−c_HL = 0), there was a fixed trade-off between the two signals (c_LH−c_LL = c_HH−c_HL = 1500), or the trade-off between the two signals was condition-dependent (c_LH−c_LL = 1500; c_HH−c_HL = 200).)

treatment no.	trade-off	low-quality signaller		high-quality signaller		expectation by the Handicap Principle	expectation by game theoretical models
		low-intensity signal	high-intensity signal	low-intensity signal	high-intensity signal
		cLL	cLH	cHL	cHH
1.	no	0	0	−100	−100	dishonest	dishonest
2.	yes	0	1500	−1600	−100	dishonest	dishonest
3.	condition-dep.	0	1500	−300	−100	dishonest	honest
4.	no	0	0	0	0	dishonest	dishonest
5.	yes	0	1500	−1500	0	dishonest	dishonest
6.	condition-dep.	0	1500	−200	0	dishonest	honest
7.	no	0	0	100	100	honest	dishonest
8.	yes	0	1500	−1400	100	honest	dishonest
9.	condition-dep.	0	1500	−100	100	honest	honest