The color red has a strange power over our unconscious minds. Recent research suggests it can increase one’s attractiveness, compel teachers to grade papers more harshly, and even prompt people to get vaccinated for sexually transmitted diseases.

Now we can add to the list: It can trick men into overpaying for “sale priced” items.

A study in the June issue of the Journal of Retailing reports that, in a series of experiments, “Male consumers perceived greater savings when prices were presented in red than when presented in black.”

Red can increase one’s attractiveness, compel teachers to grade papers more harshly, and even prompt people to get vaccinated for sexually transmitted diseases.

“When men see prices in red, they feel more positively and perceive greater savings,” write researchers Nancy Puccinelli, Rajesh Chandrashekaran, Dhurv Grewal, and Rajneesh Suri. “In contrast, women appear immune to the effects of prices in red, due to their tendency to process ads in greater depth.”

In one experiment, 163 graduate business students at an East Coast university were asked to imagine they were setting up an apartment. They then looked at a mock retail ad featuring three toasters and two microwave ovens.

Half saw a version of the ad in which the prices were printed in black ink; the others saw an alternate version in which the figures were in red. After examining them, participants were asked to (a) evaluate whether they felt the store was offering genuine bargains, and (b) describe their emotional state—specifically how happy, pleased, and glad they were feeling at that moment.

The results: “Males perceived greater savings at the store when the prices in the retail ad were presented in red,” the researchers report. “However, no such effect of color was observed for female participants.”

This perception appears to be emotion-driven. Men who viewed the red prices reported they were feeling more positive emotions, compared to men who looked at the black prices. The color did not have this effect on women.

For another experiment, featuring 152 graduate students, participants indicated their level of knowledge about toasters and microwave ovens, and their “interest in learning about kitchen appliances.” They then viewed the aforementioned ads.

The gender difference again appeared, but only among men with relatively low levels of knowledge or interest in the items. This suggests that the red-equals-savings trick only works when men aren’t particularly engaged, and are thus more susceptible to such cues.

So the message seems to be: Don’t send your husband to the store to buy a new microwave, or any other appliance he’s uninterested in. If the store is savvy enough to print the prices in red, he’s apt to come home having spent too much.