Page 147 - Demo

Absence of cognitive bias to flanges in orang-utans1456have an influence on the preference: the orang-utans were more likely to select the flanged male stimulus if these were associated with the red dot (ORGreen = 0.67 [0.08], 89%CrI [0.54; 0.83], pd = 0.99), indicating a preference for the colour red (Figure 5). Furthermore, we found very strong evidence for the notion that orangutans made energy-efficient choices (Supplementary Table 4; Figure 6): they were more likely to select the flanged stimulus when the dot associated with it was presented in the lower portion of the screen (ORHeight = 17.01 [5.06], 89%CrI [9.42; 25.64], pd = 1.00).In addition, we explored whether individuals showed temporal clustering in their choices by selecting the same category multiple times in a row. To this effect, we compared the number of switches between categories for every session to a dataset consisting of the number of switches that one would expect under the assumption of independence. We found no evidence for temporal clustering (fewer switches than expected) or temporal dispersal (more switches than expected) in any of the sessions, indicating that previous choices did not influence choices in the next trial.Figure 5 – Posterior predictions of the probability of selecting the flanged male stimulus as a function of the colour associated with flanged male stimuli per subject. The horizontal line indicates chance level.Tom Roth.indd 145 08-01-2024 10:41