Though blushing remains one of the most intriguing human expressions, scientist have gotten one step closer to uncovering the secrets behind the sudden rush of color to our faces. 

For ages, scientists questioned whether blushing occurred when humans were alone or in the dark. But with the help of heat-sensitive cameras, a research team has finally confirmed that we do indeed blush in the dark, the Telegraph UK reports.

The team was comprised of researchers from the Germany's University of Erfurt and the Dutch Academy of 'Pataphysics in Amsterdam. Though the instruments that they employed for the study has been around for several years, they had never been used to complete a test on blushing. 

To get the job done, Denise Wächter and Wolter Seuntjens used a thermogenic camera in a blacked-out room and filmed the face of a 31-year-old woman described as having a "talent to blush easily."

After she became acclimated to the room's temperature, they took one set of pre-blush measurements of the woman, according to the Daily Mail. They then asked her to tell them of an embarrassing incident she had experienced. When the woman told the researchers she felt she was blushing, they took a second measurement that revealed an increased amount of heat in her face. 

"By showing that people can blush in the dark we have finally solved this age-old problem," the researchers reported in the Annals of Improbable Research.

The Annals of Improbable Research is a journal that focuses on witty or weird studies which "make people laugh and then think," says a statement on the journals site.

The researchers added that more studies would need to be completed to see how often people blush when they are alone compared to when they are in group settings. This could serve to uncover how much of a "social" gesture it is. 

"Perhaps the individual's propensity to blush when alone may prove to be a diagnostic and prognostic personality trait. In the case of blushing this trait might indeed be a measure for 'modesty,'" they said.

Each year the the AIR awards the creators of the most improbable research the "Ig Nobel Prizes." This year's ceremony will take place next week at Harvard University.