The parasite Toxoplasma gondii is a single-cell organism that infects many other species, but ultimately wants to infect cats. It can go through various life cycles waiting for an opportunity to return to a cat, where it can reproduce. The disease caused by the infection is toxoplasmosis, which is fairly common and produces no symptoms in the vast majority of humans. However, T. gondii can alter behavior in humans and other animals. Can it even make us look different?
An international team conducted an experiment in which they separated 213 participants into groups by whether they carried the T. gondii parasite. Among other data collected, their pictures were rated for attractiveness by another group of 205 participants. They found a significant different in attractiveness ratings. The group that had the parasite were judged to be more attractive! A closer look found that the group with the parasite had more symmetrical features, which is one known factor of beauty. And infected men have been shown by earlier studies to have higher testosterone levels. How does a parasite do that?
One logical explanation is that the parasite is not the cause of the attractiveness, but rather that more attractive people have a higher tendency to encounter the parasite, as in they have more social contacts and more sexual partners. Read more about this research at Real Clear Science.
(Image credit: Jitinder P. Dubey)
