University of Delaware psychologists say that jealously may literally impair vision.

In a recent study published in Emotion, the researchers found that women who were made to feel jealous were so distracted by unpleasant emotional images they became unable to spot targets they were trying to find.

It has long been known that the emotions involved in social relationships affect mental and physical health, but these results extend the relationship a step further, to the point that emotions affect what we see.

In a lab experiment, researchers had romantic partners sit near each other at separate computers. The woman was asked to detect targets (pictures of landscapes) amid rapid streams of images, while trying to ignore occasional emotionally unpleasant (gruesome or graphic) images.

The man was asked to rate the attractiveness of landscapes that appeared on his screen. Partway through the experiment, the experimenter announced the male partner would now rate the attractiveness of other single women.

At the end, the females were asked how uneasy they felt about their partner rating other women's attractiveness.

The finding? The more jealous the women felt, the more they were so distracted by unpleasant images that they could not see the targets. This relationship between jealousy and "emotion-induced blindness" emerged only during the time that the male partner was rating other women, helping rule out baseline differences in performance among the women.

The researchers don't yet know what will happen when the roles are reversed; in these experiments, it was always the women who searched for a target. Future research might reveal whether men tend to be less or more blinded by jealousy.

Citation: Most et al., 'Blind jealousy? Romantic insecurity increases emotion-induced failures of visual perception.', Emotion, Apr 2010, 10(2); doi:10.1037/a0019007