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Is that Me or My Twin?


A team of researchers coordinated by Salvatore Aglioti, Director of Sapienza's Social Neuroscience Laboratory and a researcher at the Santa Lucia Foundation in Rome, together with the Twin National Registry of the Istituto Superiore di Sanità, analysed the ability of monozygotic twins to distinguish their face from that of their twin’s.

The research project analyses the ability of twins to recognised themselves in the mirror, an ability that is specific to mankind and a few other animal species, as it is at the basis of complex cognitive abilities such as self-awareness. Monozygotic twins are an interesting exception in this context, as their faces are almost identical. The researchers showed each twin photographs of friends, relatives, their twin and of themselves. While individuals generally easily recognise photographs of themselves, this is not the case for monozygotic twins whose faces are virtually identical. They normally have to rely on other senses, such as touch.

"A twin’s inability to recognise themselves over their twin,” explains Ilaria Bufalari “seems to depend on the degree to which twins perceive themselves as physically similar to each other, as well as on certain traits of their personalities. In fact, this difficulty is greater in twins who have developed, in their relationship with others, a behaviour of "insecure attachment," often associated in psychology with a negative view of oneself.”

The study, which has been published on the Plos One Journal, also received an Ig Nobel Award.

References: Is That Me or My Twin? Matthias Martini, Ilaria Bufalari, Maria Antonietta Stazi, Salvatore Maria Aglioti Plos One Published: April 8, 2015 Lack of Self-Face Recognition Advantage in Identical Twins