Why is a person able to experience sexual arousal 365 days a year? Answer found
Many mammals are capable of breeding only during certain periods. But not a person: in our species, all healthy sexually mature individuals are ready for procreation all year round. Moreover, a human woman is not always capable of conception, but is always capable of experiencing sexual desire.
From an evolutionary point of view, this may seem like a waste of energy, but scientists from Norway and the USA have found that a woman’s sexual activity during periods that are inappropriate for conception can also be a useful evolutionary mechanism. It helps strengthen relationships in a pair, scientists say.
To find out how a normal female libido affects a couple when a woman is unable to conceive a child, the researchers analyzed the results of surveys of fidelity to a regular partner among women whose period was artificially extended with the help of hormonal contraceptive drugs.
An egg ready for fertilization lives in the woman’s body for only a day — others, and then either develops into the fetus or is removed from the body. The moment when the egg is developed enough to merge with the sperm, is preceded by a sharp decline in the production of estrogen and the simultaneous start of the production of the hormone progesterone. Throughout the rest of the cycle, a woman is unable to conceive. Oral contraceptives change the amount of hormones in the blood or in such a way that the egg does not develop at all.
A study by Norwegian scientists showed that in women who use hormones of the first type, the relationship between the number of sexual acts and fidelity to a partner is less pronounced. When estradiol levels fall and progestin rises, this dependence, on the contrary, becomes more apparent. Similar data was obtained by American experts, interviewing women who did not use any drugs for family planning.
What do these results tell us about the evolutionary role of female sexuality during periods when conception is impossible? Scientists conclude that the ability and desire to initiate sex at a time when conception is not possible helps women to remain in a stable relationship. Perhaps, they believe, this is the meaning of the regime of sexual activity 24/7/365 in people: it helps to stay with a partner, which increases the chances of survival and, ultimately, procreation.
The results of the study are published in the journal Evolution & Human Behavior . Unlike other similar polls, the results were reproduced in a repeated study, the authors note.