Sex, and other important things: Tracking ratios of ecologically significant categories.

Abstract

The ratio of males and females in a population (the sex ratio) has been documented as an important factor in calibrating mating behaviors. This implies mental processes of attention, perception, categorization, and memory to obtain these environmental sex ratios. Although recent work has indicated that sex ratio information can be processed quickly, accurately, and with little effort, there are still open questions about whether sex ratio information is cognitively privileged or prioritized, relative to other environmental information. The present experiments used an ensemble coding paradigm with larger, more complex matrices of stimuli and with a more feasible range of ratios (between 7:13 to 13:7) than many prior studies on sex ratio perception. Experiment 1 found that sex ratio estimates are sensitive to actual seen ratios (of a 4 3 5 matrix of faces, shown for about 500 ms), and that those judgments are more accurate than similarly presented ensemble coding judgments for vehicles (ratios of cars and truck) or for animals (ratios of cats and dogs). Experiment 2 found that sex ratio estimates and hair color ratio estimates are about equal in accuracy. These results together suggest that faces are a privileged content for frequency tracking, relative to other aspects of the environment. Further research can extend this work by disambiguating factors such as complexity and discriminability of various facial cues and the stage of processing at which those cues are being used.