- T gondii might be making its human hosts more attractive to opposite sex.
- Making host more attractive means it can spread more easily.
- Infected men had higher facial symmetry and testosterone.
Nearly half of the world’s population is infected by a common parasite Toxoplasma gondii (T gondii).
A new study published in the journal Peer J has shown that this parasite might be making its human hosts more attractive to the opposite sex to promote more sexual activity so that it can spread more.
Previous studies revealed that T gondii in rats made them attracted to the urine of predator cats. Due to this, rats involved themselves in riskier behaviour which increases the chances of cats eating rats and the parasite eventually entering cat bodies which is an optimal host.
The parasite did not only manipulate rats but also hyenas, chimpanzees and humans. Making the host more attractive means it can spread more easily.
On the contrary, animals may avoid mating with other animals that seem sick. (that is, infected by a parasite). To solve this problem, T.gondii worked on how attractive female rodents found male rodents. Some believe the parasite could do the same in humans.
T.gondii can change rats’ behaviours. This is what led researchers to test whether the parasite was doing the same in humans.
Some studies have shown that T.gondii does influence human traits. For example, studies have shown that infected males have higher levels of testosterone.
The most recent study showed that infected men had higher facial symmetry. Similarly, women infected with T.gondii had lower body mass with better self-perceptions of attractiveness.
In the second part of the research, respondents were shown many photos of infected and uninfected people. They were asked to rate the pictures for attractiveness and health.
Those infected with T.gondii were rated more attractive consistently.
While it is still unclear how exactly the unicellular creature is able to bring about such changes, it is now known that it is highly manipulative.