Table 3.

The role of inhibitory control ability in explaining variation in co-representation

Species	Fixed factor	β	SE	95% CI	OR	z	p
Overall	Intercept	1.10	0.17
	Compatibility	− 1.75	0.17	− 2.09, − 1.42	0.17	− 10.37	< 2 × 10–16***
	Inhibition	− 9.68 × 10–4	0.00	− 0.01, 0.00	1.00	− 0.37	0.71
			N = 17 individuals, ${\chi }_1^2$ = 0.13, p = 0.72, ∆AIC = 1.87
Tonkean macaques	Intercept	1.36	0.36
	Compatibility	− 2.70	0.34	− 3.37, − 2.03	0.07	− 7.89	2.98 × 10–15***
	Inhibition	− 7.28 × 10–5	0.01	− 0.02, 0.02	1.00	− 0.01	1.00
				N = 7 individuals, ${\chi }_1^2$ = 0.00, p = 1.00, ∆AIC = 2.00
Brown capuchins	Intercept	3.49	3.68
	Compatibility	− 2.15	0.38	− 2.90, − 1.41	0.12	− 5.66	1.53 × 10–8***
	Inhibition	− 0.03	0.04	− 0.11, 0.06	0.97	− 0.64	0.52
			N = 5 individuals, ${\chi }_1^2$ = 0.41, p = 0.52, ∆AIC = 1.59
Common marmosets	Intercept	0.90	0.18
	Compatibility	− 1.08	0.23	− 1.54, − 0.63	0.34	− 4.65	3.32 × 10–6***
	Inhibition	5.75 × 10–4	0.00	− 0.01, 0.01	1.00	0.17	0.86
			N = 5 individuals, ${\chi }_1^2$ = 0.03, p = 0.86, ∆AIC = 1.97

The effect of inhibitory control ability assessed with a detour-reaching task on an individual’s strength of co-representation (i.e., joint Simon effect; errors in incompatible vs. compatible trials) overall across the three tested species (n = 17), and separately in the Tonkean macaques (n = 7), the brown capuchins (n = 5), and the common marmosets (n = 5). Parameter estimates, standard errors, 95% confidence intervals (CI), odds ratios (OR) and statistical significance are obtained from generalized linear mixed effect models. Significant effects are indicated with p-values in italics