In general, it is women who turn off the air conditioning in the car, or raise the temperature of the one in the office. Or they add an extra blanket to the bed in winter. But what is the reason why women tend to feel colder than men?
As revealed by a new study published in the magazine Global Ecology and Biogeography, These differences in the thermal sensation would be something that not only happens with human beings and everything indicates that it would be related to reproduction.
Researchers at the Faculty of Zoology at Tel Aviv University in Israel found an evolutionary explanation to justify the endless everyday scenes in which a woman bundles up, while their male counterparts are most comfortable wearing short sleeves with air conditioning.
In addition, they concluded that this phenomenon is not only exclusive to humans, since in many species of endotherms (birds and mammals) the males prefer a cooler temperature than the females.
“We propose that males and females feel temperature differently. It is a built-in evolutionary difference between the heat detection systems of both sexes, which is related, among other things, to the reproduction process and the care of the offspring “, the researchers noted.
The study was led by Drs Eran Levin and Tali Magory Cohen, from the Faculty of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University, Yosef Kiat, from the University of Haifa, and Dr. Haggai Sharon, a specialist in pain from Tel Aviv University Sackler School of Medicine and Tel Aviv Sourasky Medical Center (Ichilov Hospital).
Both researchers explained that “this difference in thermal sensation did not arise so that we could argue with our partners about the air conditioning, but rather the opposite: it is intended for the couple to take a certain distance from each other so that each individual can enjoy something of peace and tranquility ”.
“The phenomenon can also be related to sociological phenomena observed in many animals and even in humans, in a mixed environment of females and males: females tend to have much more physical contact with each other, while males maintain more distance and avoid the contact with each other ”, they added.
The study, which included more than 11,000 individual birds and bats, from Mount Hermon in the north to Eilat in the south, He also developed an in-depth statistical and spatial analysis of the distribution of dozens of bird and bat species living in Israel, along with a comprehensive review of the international research literature on the subject.
Dr. Levin, who among other things studies the physiology and behavior of bats, had observed in previous studies that during the breeding season males and females tend to segregate, with males inhabiting colder areas. For instance, Entire colonies in caves on the slopes of Mount Hermon are made up only of males during the breeding season, while in the warmer part of the Sea of Galilee there are mainly females, who give birth and raise their cubs there. It was this phenomenon that aroused his curiosity and triggered the present investigation.
Among many mammals, even in species that live in pairs or in mixed groups throughout their lives, males prefer shade while females prefer sunlight, or males ascend to mountain peaks while females remain in the valleys.
The reasoning behind the choice of birds and bats for the study is the fact that they fly and are therefore highly mobile, and The researchers hypothesized that the spatial separation between the sexes – sometimes extending to different climatic zones – would be especially clear in these groups. Furthermore, Israel’s significant climatic diversity allowed them to study individual animals of the same species living in very different climatic conditions.
The results of the study clearly demonstrated that males prefer a lower temperature than females, and that this preference leads to a separation between the sexes at certain periods of the breeding cycles, when males and females are not needed, and even they can interfere with each other.
“Our study has shown that the phenomenon is not unique to humans; Among many species of birds and mammals, females prefer a warmer environment than males, and at certain times these preferences cause segregation between the two species ”, explained Levin, who added:“ In light of the findings, and of the fact that it is a generalized phenomenon, we have hypothesized that it is a difference between the heat detection mechanisms of females and males, which has developed throughout evolution ”.
In the same line, The authors of the work considered that “this difference is similar in its essence to the known differences between the pain sensations experienced by the two sexes, and it is affected by the differences in the neuronal mechanisms responsible for the sensation and also by the hormonal differences between males and females “.
Dr. Magory Cohen notes that this difference has several evolutionary explanations. First, the separation between males and females reduces competition for environmental resources and drives away males who can be aggressive and endanger the young.. In addition, many female mammals must protect their young at a stage where they are not yet able to regulate their body temperature on their own, so they developed a preference for a relatively warm climate.
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