Table 1. Relative contributions of number and cumulative area on classification.

Group	Number weight (s.e.)	Cumulative area weight (s.e.)	Observations
Monkeys	0.126***	0.027	380
	(0.027)	(0.143)
4-5-year-olds	0.381***	0.095**	864
	(0.067)	(0.034)
Tsimane' adults	0.681***	0.309***	714
	(0.081)	(0.054)
US adults	0.805***	0.062	2,436
	(0.121)	(0.091)

Note: *P<0.05; **P<0.01; ***P<0.001.

Beta weights (and s.e.) from mixed effects logistic regressions predicting ‘category choice' using ‘number' and ‘cumulative area' stimulus values as predictor variables and subject as a random effect. The coefficients have been centred but not standardized. The total number of probe observations is shown for each group (US adults: n=21, observations per subject=116; US 4-5-year-olds: n=27, observations per subject=32; Tsimane' adults: n=51, observations per subject=14; Monkeys: n=2, observations per subject=176 and 204).