At the same time, the researchers studied their brain waves and noted their response times.
Their findings - published by journal Frontiers in Neuroscience - showed that men were more likely to accept bad deals from the women in the attractive group. They were also quicker to respond to fair offers from good-looking women and slower to respond to unfair offers.
The team believe the delay is due to volunteers weighing up the "value" of facial attractiveness - before adding it to the worth of the monetary offer.
They said: "The enjoyment of the perceived beauty could relieve the subjects' dissatisfaction with an unequal money distribution."
Meanwhile, brain scans revealed that men were more sensitive to unfair offers when the woman was plain, and felt more reward when the woman was good looking.
The researchers claim that "lookism" creates inequalities comparable to those created by racism, sexism, and family background.
Previous research has found that people of above average beauty earn around 15 per cent more - while those with average looks pay a "plain penalty" in earnings.
"He's a lot more helpful since he was hypnotised into thinking I'm Angelina Jolie."
- Daily Mail