Cognição e personalidade coletivas em Dorymyrmex thoracicus

Abstract

Ants are socially organized and have sophisticated means of communication, mainly through pheromones. Intense communication can allow the application of the concept of collective cognition and consequently imply the existence of a collective personality. The general objective of this work was to test the existence of a correlation between collective cognition and collective personality in Dorymyrmex thoracicus. Specifically, it was intended to: Measure the cognitive ability of collective decision-making and evaluate conditions in which the ability of collective decision-making manifest more easily; Measuring the exploration trait of the collective personality in colonies; Correlate collective cognition with collective personality. We hypothesized that there would be no correlation between collective personality and collective cognition, when the size of the social group was statistically controlled. Initially, 28 colonies of Dorymyrmex thoracicus were selected in the field, for which the relative size of each was estimated based on the radius of loose sand in the nest. Two types of food resources of different sizes were offered, from which traffic flow and speed were measured to detect a possible choice. Subsequently, the collective personality of the colony was measured, based on the stability in repeated measures of exploration behavior. To analyze cognition data, we verified whether the choice for the large bait in relation to the small one was greater in the experimental group than in the control group and the statistical analysis was performed using the paired t test. The existence of collective personality was assessed using the linear mixed modeling (LMM). As results, we found collective cognition in all colonies studied: flow p=0.003 and speed p=0.026, as well as collective personality R=0.465 and p=0.002. These findings corroborate the literature, but we did not find a correlation between them: collective personality and flow p=0.916 and collective personality and speed p=0.350, however this correlation may occur not due to the bond itself, but due to a relationship with another variable. We conclude that there was no correlation between the cognitive ability of collective decision-making and the collective personality exploration trait, and we discuss how theoretical and methodological factors can contribute to explaining this.