Evidence of adaptation for mate choice within women's memory

In humans, sexually dimorphic features advertise long-term health and reproductive potential to prospective partners. Evolution has accordingly adapted our cognitive faculties so that we perceive sexually dimorphic features as important when judging other people’s attractiveness and suitability as a potential mate. Here we provide evidence showing, for the first time, that long-term memory also responds adaptively to the presence of sexually dimorphic cues. Human females’ memory for event-specific details was found to be enhanced when these details co-occurred beside images of masculinised vs. feminised male faces. This effect co-varied with preference for masculine vs. feminine studied male faces, and was only observed in female individuals not taking oral contraceptives. The analogous pattern was entirely absent in males. These findings reveal a preference and condition dependent memory enhancement in females that will promote retention of information from encounters with male individuals of high phenotypic quality. We propose that human females’ memory for recently experienced episodes may therefore be functionally specialised for mate choice, and in particular for the comparative evaluation of alternative mates. We also suggest that similar specialisation may be present in other animal species where it has been established that precursor, ‘episodic-like’, forms of memory exist, and we describe how this might be tested experimentally.