A multidisciplinary team of researchers studied a large body of texts to find out how people in the ancient Mesopotamian region (within modern day Iraq) experienced emotions in their bodies thousands of years ago, analyzing one million words of the ancient Akkadian language from 934–612 BC in the form of cuneiform scripts on clay tablets.

The results of the research were published in the iScience journal on 4 December.

"Even in ancient Mesopotamia, there was a rough understanding of anatomy, for example the importance of the heart, liver and lungs," says Professor Saana Svärd of the University of Helsinki, an Assyriologist who is leading the research project. One of the most intriguing findings relates to where the ancients felt happiness, which was often expressed through words related to feeling 'open,' 'shining' or being 'full'––in the liver.

"If you compare the ancient Mesopotamian bodily map of happiness with modern bodily maps [published by fellow Finnish scientist, Lauri Nummenmaa and colleagues a decade ago], it is largely similar, with the exception of a notable glow in the liver," says cognitive neuroscientist Juha Lahnakoski, a visiting researcher at Aalto University.

Other contrasting results between ourselves and the ancients can be seen in emotions such as anger and love. According to previous research, anger is experienced by modern humans in the upper body and hands, while Mesopotamians felt most 'heated,' 'enraged' or 'angry' in their feet. Meanwhile, love is experienced quite similarly by modern and Neo-Assyrian man, although in Mesopotamia it is particularly associated with the liver, heart and knees.