. Author manuscript; available in PMC: 2011 Oct 1.

Published in final edited form as: Behav Processes. 2010 Jun 30;85(3):236–245. doi: 10.1016/j.beproc.2010.06.014

Table 2.

Mean percentage and standard deviation of complementary confusion errors for all 4 nonreinforced categories and for all 8 birds in Experiment 1 (chance level at 25%). Bold font indicates the complementary category (S−s from the same category as S+s).

Reinforced category	Nonreinforced Category
	Car		Chair		Flower		Person
	M	SD	M	SD	M	SD	M	SD
Car	44.1^*	8.0	14.8^!	4.0	18.9^!	5.6	22.3	4.6
Chair	13.5^!	2.9	35.3^*	6.5	30.0	9.7	21.2^!	4.1
Flower	10.9^!	2.7	21.4	4.4	49.8^*	7.2	17.9^!	6.3
Person	17.1^!	4.9	20.3^!	4.3	21.8	5.5	40.8^*	8.9

Significantly above chance, two-tailed t-test, n = 8, p < 0.05

Significantly below chance, two-tailed t-test, n = 8, p < 0.05