Parental instinct: what we traded you for

Video. In which Akuaku is taking care of a cat and swaddling a wombat, a newborn giraffe falls into the world, a person is breastfeeding a rodent, Professor Dubynin gives a valuable life hack about male nipples, rats are choosing between children and cocaine, and the birthday girl explains what kind of trash parental behavior in higher mammals is made of. More births on my birthday!

Fragments of text for those who love text.

The parental behavior of rats consists of the same basic elements as human parental behavior: building a nest, carrying, adopting a nursing posture, and grooming the offspring. However, these elements are programmed much more rigidly (especially the last one).

But even these simple patterns don’t just fall from the sky. They need to be activated by internal and external stimuli.

The internal stimulus is hormones. During pregnancy in mammals, levels of estrogen and progesterone rise, but before giving birth, they drop, while oxytocin and prolactin spike. These hormonal fluctuations awaken the maternal instincts in a rat. Even if she is a virgin, and even if she is a male.

There was an experiment. Non-pregnant rats were injected with progesterone and estrogens, and then with oxytocin and prolactin, mimicking the hormonal profile before giving birth. And lo and behold, the rat started building a nest and dragging cotton balls into it! Even if it was a virgin (or a male virgin).

As I mentioned before, our instincts have faded away like the Cheshire Cat: the structure is gone, but the smile still remains. The echoes of nesting behavior linger on. It’s the ninth month, I’m sleeping poorly, and moving around is a struggle. Should I go ahead and do some renovations throughout the apartment?

But finally, it’s time for labor! According to research by neurologist Dick Swaab, the timing of childbirth is determined by the baby’s brain. It’s getting a bit cramped in here, and they can’t keep up with the cleaning, so I think I’ll go ahead. This first decision of our lives sets the process in motion. Oxytocin levels rise, triggering contractions, and when the baby’s head passes through the cervix, the stimulation further increases oxytocin levels. The circle is complete! In the final moments of their symbiosis, the mother and baby’s brains are literally bathed in oxytocin. And this changes them forever.

By the way, the release of oxytocin due to cervical stimulation is that very magic that can turn a light crush into a terrifyingly deep love after just one good sexual encounter. Reaching the brain — done.

Oxytocin is the chemical foundation of the bond between a mother and her offspring, and everything that has grown from that: warm social connections, friendship, affection, love, and the desire to start a relationship, get a cat, or a dog. As a hormone, it triggers uterine contractions and milk production, while as a neurotransmitter, it fosters the desire to love, hug, warm, feed, protect, dedicate the best years to someone, and when necessary, to fight fiercely. This is because oxytocin works in two directions: it enhances love, care, and attachment to one’s own, while increasing aggression towards others—enemies or competitors. Because only my own, my little ones, should eat well! Oxytocin is the hormone of love, but this love can come with a punch. For example, here’s a discussion about its role in chimpanzee wars: https://elementy.ru/novosti_nauki/432907/Mezhgruppovye_konfl Пожалуйста, предоставьте текст для перевода.
Parental care is a useful thing and helps effectively pass on one’s genes to the future. But animals, including many humans, know nothing about genes and don’t think about the future. Well, humans have words like “must” and “don’t even think about it!” But what makes animals expend energy on fussing over helpless little ones instead of abandoning them, or even better, eating them? You won’t believe it, but they do it simply for pleasure.

Tying pleasure to evolutionarily advantageous behaviors—such as eating, playing, learning, and having sex—is a brilliant invention of natural selection. Those who didn’t enjoy eating went extinct. Those who didn’t like having sex didn’t pass on that trait. Caring for children is enjoyable; otherwise, believe me, no one would lift a finger for them. To sweeten the daily routine of parenting, evolution has provided the sweetest neurochemical treats: in addition to oxytocin, there’s dopamine, serotonin, and endorphins—natural painkillers and euphoric endogenous opioids.

Yes, children are like drugs, only legal and very expensive. Scientists discovered this by cunningly administering naloxone—a drug that blocks the pleasurable effects of morphine and endorphins—to mother macaques. And they immediately lost interest in their parental duties. “Some kind of fake offspring. They look real, but there’s no joy at all.”

Or there was another interesting experiment: first-time mother rats were given a choice between caring for their pups or a solution of cocaine. And the young mothers chose cocaine.

Well, girls, scientists said – and they repeated the experiment on experienced mothers. And guess what, they preferred to take care of their children. The secret of natural neurotransmitter bliss is that the more you practice, the better you get, and the more joy you receive. So beware of cheap imitations! True pleasure comes only from real children.

If the brain for some reason doesn’t release the goodies, parental behavior is disrupted. For example, the stress hormone cortisol suppresses the production of oxytocin, and instead of feeding her offspring, the mother ends up eating them. Something is not right here, kids; someone is going to eat you anyway, so it’s better if it’s your own mother.

People have a similar story. Stress during pregnancy is a major risk factor for postpartum depression. Oxytocin is suppressed by cortisol, the baby doesn’t bring joy, which makes me feel like a bad, bad mother. A similar effect can be caused by hormonal imbalances due to young age or other factors. When hormones stabilize, either on their own or with the help of doctors, it passes. The main thing is not to end up consuming either the children or oneself.

Parental behavior can be disrupted if the offspring does not meet the standards programmed in the brain: if it doesn’t look right, doesn’t smell right, doesn’t stand right, or doesn’t make the right sounds—this can also block parental behavior and trigger feeding behavior instead. Therefore, if possible, avoid being a weak and sickly offspring in the animal world. And don’t listen to those who say, “Animals never abandon their young!” These people are very misinformed.

… From early childhood, we practice being parents. When we play with dolls, feed stuffed animals, put toy guns and cars to bed, and take care of our younger siblings, we are mimicking our parents’ behavior, and this serves as a rehearsal for the neural pathways of our own parenting behavior. And of course, it’s a source of neurochemical pleasure.

Dutch primatologist Frans de Waal has shared that adolescent macaques love to play with infants. If they manage to coax a baby away from its mother, they run around with it, sniffing and licking it—only to suddenly fall asleep out of nowhere, literally conking out for a few minutes.

— What’s wrong with him?

— Overdose. Oxytocin.

This can happen in both young females and males. The same centers for parental behavior exist in the male brain, and they can be activated even in species that do not practice paternal care. Electrical stimulation of the medial preoptic area of the hypothalamus prompts a rooster to incubate eggs, and a male rat to carry toy rats. So, all you guys can do it; you just need to want it or give your hypothalamus a little nudge.

Moreover, if you artificially increase the levels of oxytocin and prolactin in male mammals, their mammary glands start to produce milk because they actually have everything needed for this; you just need to add the hormone. In nature, milk is only produced by male flying foxes. But if someone wanted to become Batman, keep that in mind.

Well, here’s a male of some mammal ready to take care of a young one. But how does he know that this is his offspring? Just like human males before the invention of paternity tests: he doesn’t. Moreover, animals generally have no idea that children and sex are somehow connected. For both males and females, sex is purely a pleasure, while children are something entirely different. Some tribes, by the way, still believe this today.

But what does it change? The male is bound to his female by the very oxytocin-vasopressin ties that underlie love. The pregnant female gradually becomes more and more like a large baby—round, cute, clumsy, emotional, sleeping poorly, and constantly wanting to be held. All of this greatly stimulates the male’s anterior hypothalamus and activates his parental behavior. He builds a nest, cares for the female, feeds her, and when the offspring are born, he naturally shifts his focus to taking care of them.

However, while 85% of bird species have males that care for their offspring, only five percent of mammals have such involved fathers. So who’s to blame? The females are to blame. Mammal mothers have set things up in such a way that it’s quite difficult for the males to get involved. First, the fetus develops under the full protection of the mother’s body, and then it is fed with milk until it is ready. Girls, you’ve come up with such a great system that we really have nothing to add, so we’ll just take our leave.

But people belong to the 5% of the lucky ones. We are a biparental species, and throughout our evolutionary history, except perhaps for the last few decades, both parents have been needed to raise a child (the most precious and long-growing being in the world). For obvious reasons, the genes of good fathers have been more successfully passed down in the population — including alleles associated with paternal care. When these fathers interact with their child and the child’s mother, their levels of estrogen, oxytocin, and prolactin increase, activating the parental network, a neural circuit that governs emotions, attention, vigilance, the pleasure derived from rewards, as well as learning and analyzing experiences. This neural circuit functions better the more a father cares for his child.

Experiments show that the presence of offspring stimulates the growth of new neurons in the hippocampus of male voles, a part of the brain responsible for memory consolidation. Guys, you are no worse than voles, so your hippocampus is thriving with fatherly duties—just look at that! Because great fathers, just like great mothers, are not born; they are made. Or not made.

Our parenting behavior is like a weapon in a video game. Some basic tools are given to us by default, but we have to gather the main arsenal ourselves. Playing on minimal settings can be quite a challenge. However, the better you level up, the more joy you’ll get from the experience.

But what if you really don’t want to play house? That’s perfectly fine too. In the context of global urbanization and increasing population density, it’s not about having many children, but about raising them well. And it’s not necessary to raise your own. In a hyper-social species, there are no such things as other people’s offspring. For example, twice a week, I have about thirty kids come to me, and I love them all very much. Partly because I get to hand them back to their parents after the session. Kids are like dolphins: I enjoy playing with them, teaching them various things, but I don’t need another dolphin of my own.

*****.

Thank you for the congratulations and enjoy!