Table 1.

Summary of results obtained across experiments when comparing contributions offered in painful–effortful and easy–enjoyable fundraisers

		Effect size	Sample size
	Relative increase in mean contributions (%)	d	N	Charity/cause
Experiment 1a (endurance run vs. picnic)	72	0.70	96	Asian tsunami
Experiment 1b (endurance run vs. picnic)	59	0.51	96	Hurricane Katrina
Experiment 2 (cold pressor vs. control)	31	0.70	36	Public pool (collective)
Experiment 4 (endurance run vs. picnic)	213	0.61	357	Victims of war and genocide
Experiment 5 (30-h fast vs. picnic)	93	0.58	76	Starving children in poor countries
Average [total]	94	0.62	[661]

Note. In all these comparisons, the mean amount contributed was greater in the painful–effortful condition than in the easy–enjoyable one.