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Fluctuating asymmetry and physical health in humans
Research has linked higher levels of fluctuating asymmetry (FA) to poorer outcomes in some domains of physical health in humans. For example, one study found that individuals with higher levels of FA report a higher number of medical conditions than those with lower levels of FA, but did not experience worse outcomes in areas such as systolic blood pressure or cholesterol levels. Higher levels of FA have also been linked to higher body mass index (BMI) in women, and lower BMI in men. Research has shown that both men and women with higher levels of (both facial and bodily) FA report a higher number of respiratory infections and a higher number of days ill, compared to men and women with lower levels of FA. In men, higher levels of FA have been linked to lower levels of physical attractiveness and higher levels of oxidative stress, regardless of smoking or levels of toxin exposure.

A large-scale review of the human and non-human literature by Møller found that higher levels of fluctuating asymmetry were linked to increased vulnerability to parasites, and also to lower levels of immunity to disease.

Fluctuating asymmetry and health-risk behaviours
It has been suggested that individuals with lower levels of FA may engage in more biologically costly behaviours such as recreational drug use and risky body modifications such as piercings and tattoos. These ideas have been proposed in the context of Zahavi's handicap principle, which argues that highly costly behaviours or traits serve as signals of an organism's genetic quality. The relationship between FA and behaviours with high health risks has received mixed support. Individuals with body piercings and tattoos (which increase risk of blood-borne infections) have been shown to have lower levels of FA, but individuals with lower FA do not engage in any more recreational drug use than those with higher FA levels.

Fluctuating asymmetry and ageing
Lower levels of FA have been associated with higher intelligence and more efficient information processing in older men, although it has been found that risk of mortality cannot be predicted accurately from levels of FA in photographs of older adults.

Fluctuating asymmetry and longevity in non-human populations
While research on the relationship between FA and longevity is sparse in humans, some studies using non-human populations have suggested an association between the symmetry of an organism and its lifespan. For instance, it has been found that flies whose wing veins showed more bilateral symmetry live longer than less symmetrical flies. The difference was greatest for male flies.

Fluctuating asymmetry and mental health in humans
Higher levels of FA have been linked to higher levels of some mental health difficulties. For instance, it has been shown that, amongst university students, higher FA is associated with higher levels of schizotypy. Depression scores have been found to be higher in men, but not women, with higher levels of FA. One study by Shackelford and Larsen found that men and women with more facial asymmetry reported more physiological complaints than those with less facial asymmetry, and that both men and women with more asymmetry experienced higher levels of psychological distress overall. For example, men with higher facial asymmetry experienced higher levels of depression compared to men with lower asymmetry.