Table 1. The mean proportion of resources shared (and standard error) in each of the four experimental conditions as a function of age group (means only include children who donated at least one sticker).

	12–1	30–1	12–2	30–2
3–4 years	.422 (.045)	.376 (.045)	.377 (.044)	.434 (.041)
5–6 years	.405 (.030)	.333 (.045)	.491 (.040)	.444 (.052)
7–8 years	.506 (.061)	.458 (.040)	.551 (.043)	.600 (.050)
9–11 years	.510 (.053)	.530 (.058)	.563 (.041)	.708 (.044)