Women are more accurate than men at recognising signs of illness in the face - study
Women are better at recognising signs of illness from their faces, scientists have found.
People often intuitively recognise when someone looks unwell - by pale skin, drooping eyelids or tired facial expressions. A new study published in the journal Evolution and Human Behaviour has found that women are on average better than men at picking up these subtle non-verbal signals of illness.
How the study was conducted
Unlike previous studies, which used edited photos or artificially "sick" faces, in the new study scientists decided to test whether people are able to recognise natural signs of ailment.
The experiment involved 280 students - equally male and female. The participants were asked to evaluate 24 photographs: 12 people were captured both in a healthy state and during illness.
They were assessed on six dimensions related to perceptions of the human condition, including feelings of safety, health, friendliness, alertness, social engagement and positivity. All characteristics were rated on a nine-point scale.
Women were found to be more sensitive
The analyses showed that women were, on average, more accurate in distinguishing between sick and healthy faces. The difference between the sexes was small, but statistically significant and stable throughout the study.
The scientists combined all the parameters into one indicator - the perception of "lethargy" or sickness. It was on this integral attribute that women showed higher recognition accuracy.
Possible evolutionary causes
The authors of the study consider two main hypotheses to explain the results obtained. The first is the so-called "primary caregiver" hypothesis. According to it, over the course of evolution, women were more likely to care for infants and children, so they may have developed a heightened sensitivity to early signs of illness.
The second hypothesis has to do with avoidance of infection. It is hypothesised that women, on average, respond more strongly to potential sources of infection. This may be due to periods of physiological immune suppression - for example, during pregnancy or certain phases of the menstrual cycle - which increased evolutionary pressure to recognise health threats more accurately.
Limitations of the study
The researchers note that the sample was limited to students and does not necessarily reflect the behaviour of the wider population. In addition, the experiment only assessed static images of faces - without taking into account voice, posture or movements, which can also play an important role in recognising disease.
Nevertheless, the authors emphasise that the work provides new evidence of gender differences in sensitivity to non-verbal signs of illness and helps to better understand the mechanisms of social perception and protection against infection.