It seems that the story of Pinocchio may be true - sort of. The nineteenth-century tale about a wooden puppet who longs to be a real boy has long been beloved by children and adults alike. In the famous tale, the boy's nose becomes longer when he comes under duress, particularly when he lies.

Now, researchers from the University of Granada have found what they dubbed "the Pinocchio effect" in humans. According to the study, when humans lie, the nose knows and, while it does not lengthen like Pinocchio's did, it heats up when a person is not telling the truth.

The effect was discovered when researchers monitored volunteers with thermal imaging software. According to the study's researchers, the tip of participants' noses heat up due to the anxiety that they felt about lying. However, that effect could be dispelled, researchers said, if participants used up a great deal of mental effort to cool their noses.

Researchers found that, when participants lied about something, it provoked a change in the brain's insular cortex, which regulates body temperature.

Emilio Gómez Milán and Elvira Salazar López wrote in their doctoral thesis that certain regions of the body change temperature according to mood. In addition to the nose, the orbital muscle in the eye's inner corner also increases and decreases in temperature.

The same study suggested that thermal imaging could pick up on sexual desire and arousal in both men and women. Sexual desire could be noted by thermal imaging cameras by an increase in temperature in the chest and genital areas.

Women also became aroused at the same time as men, even though they reported otherwise.

Researchers also took note of thermal footprints, or specific bodily temperatures associated with certain body patterns, like aerobic exercise or types of dance.

Parts of the study's results have been published in scientific journals, but not all.