快猫短视频

HE used to get up at 6.30 am so he could shower, shave, put on his suit and be at his desk by 8. His day still starts at the crack of dawn. He still works for the most discerning and demanding of clients. But nowadays there is no suit, no desk and no real need to shave. He is at the cutting edge of the latest employment trend. He is a full-time dad.

In 1986, there were 445 stay-at-home fathers in the UK. Two decades later, that number has risen to over 21,000. And in June this year, the UK鈥檚 Equal Opportunities Commission (EOC) announced that 79 per cent of men questioned said they would be happy to look after their young children while their wife or partner went out to work. In a single generation, a behaviour that was once considered eccentric has become mainstream.

This is just one illustration of a big change in social attitudes in the western world. Formerly, a father would be refused entry to a delivery room; now he may be reproached for his absence. His traditional role in family life was that of breadwinner and disciplinarian, but today childcare manuals all urge a more loving paternal approach. Where custody of children was contested, law courts have long assumed that in all normal circumstances the right place for them must be with their mother. Now the British campaign group Fathers 4 Justice is more passionately concerned about access than about alimony, and there are equivalent organisations in Canada and the US protesting on behalf of 鈥渘on-custodial parents鈥�.

The EOC report received unexpectedly wide press coverage, because the trend for men to take on traditionally female roles is still controversial. Many people welcome it, but for others it touches the same nerve as earlier reports of a drop in the sperm count 鈥� namely, a fear that something is going badly wrong with the human race. Those who fear the rise of the 鈥渘ew man鈥� condemn him as 鈥渦nnatural鈥� and assert that scientists will confirm their beliefs. That reassurance may once have been forthcoming, but now the opposite is true.

鈥淭hose who fear the rise of new man condemn him as unnatural鈥�

In the past two decades the father鈥檚 role has been re-examined and reassessed by ethologists, primatologists, endocrinologists, cultural anthropologists and sociologists. What they have found is evidence that the new man has deep evolutionary roots. What鈥檚 more, men seem to be primed to care for their offspring by the same hormone that influences women. But this caring behaviour will only come out if the social situation is right. And while the social situation for men in the western world may be making it easier for them to care for their offspring, it seems that pressures on mothers mean that the opposite is true for them. So, instead of wringing our hands in concern at the feminisation of society, we should embrace men鈥檚 evolved instincts to care for their children. Their contribution is needed now more than ever.

快猫短视频s have tended to look to the animal world to understand the role of the human father. Among amphibians and birds there are cooperative fathers, and even some species, including the ostrich, in which caring for the brood is a jealously guarded male prerogative. But the hard fact is that humans are mammals: mammals lactate, and that single act immensely reinforces the primacy of the mother-infant bond. In mammals, a father鈥檚 role tends to be minimal, frequently confined to the act of insemination. Far from caring for their young, most remain unaware of their existence. However, in a few social and predatory species such as the timber wolf, the male contributes food to the young cubs. It used to be widely assumed that among our hunting ancestors in the Pleistocene epoch the male鈥檚 role was similar 鈥� he was a prehistoric breadwinner 鈥� and that adaptations to that way of life have been hard-wired into the brains of men and women.

The first clue that things might be different came with the observation that even among mammals there are a few species in which fathers actively assist in rearing young. These are mostly rodents 鈥� a dwarf hamster, a Californian mouse, a prairie vole 鈥� and the incidence of this behaviour seems purely random. In one hamster species, Phodopus campbelli, for example, the male enthusiastically helps in caring for the young, whereas in a closely related species, Phodopus sungorus, he is totally indifferent to them. More enlightening, perhaps, are the few examples from our own group, the primates. All of them are small monkeys, including marmosets, tamarins and the titi. The last of these is so eager to become a father that he acts as midwife, helping to deliver the young, licking them and keeping them warm, and claiming the right to eat half of the placenta. Titi monkeys are exceptionally and devotedly monogamous, and seem also to be in a class of their own when it comes to parenting 鈥� the male carries his newborn for 93 per cent of the time. For both marmosets and tamarins, however, the paternal role is less intense. Fathers play their part in a system of childcare known as 鈥渃ooperative parenting鈥�, in which a mother suckles her babies and then hands them over to the nearest bystander.

These findings raised as many questions as they answered. Cooperative parenting correlates with rapidly growing young and more frequent litters, and it contributes more to infant survival than any other variable. But if the system offers such advantages, why is it so rare? And, as it has never been observed among the apes, our own branch of the primate family, can it say anything about human behaviour?

It might, if there are relevant characteristics of these small monkeys that we share, but that other apes do not. One thing we do have in common with marmosets and other small monkeys is that giving birth is a laborious and hazardous process, with high risk of death for both mother and child. The problem is head size. As a rule, among mammal species a 100 per cent increase in body size correlates with only a 75 per cent increase in brain size: smaller animals have relatively large heads, so giving birth is particularly difficult for marmosets and the like. Humans face the same predicament because in the past 500,000 years, our ancestors have spectacularly broken the rule, increasing adult brain size by around 75 per cent with little corresponding increase in body size. True, the newborn鈥檚 brain is only around a quarter its full-grown size, but even a head big enough to house that is stretching the limits of a mother鈥檚 pelvis that has evolved to be narrow enough to allow her to walk upright.

鈥淐ooperative parenting evolves whenthe mother is unable to cope alone鈥�

Difficult birthing was not the only problem that our ancestors 鈥� the hominins 鈥� shared with marmosets and tamarins in the course of their evolution. There was also the question of infant dependency and, in particular, transport. In the case of the hominins, a combination of bipedalism and loss of body hair made it much harder for them to transport their babies than it is for a chimpanzee mother. A chimp鈥檚 infants can cling to her fur when they are small and ride on her back when they begin to grow, leaving her hands free to search for food. A hominin mother must have had to carry her babies in her arms wherever she went, for months or years on end. The problem for monkeys like the marmosets and tamarins is slightly different. They have multiple births 鈥� most often twins 鈥� making it impossible for mothers to roam around in the treetops, picking fruit, while at the same time keeping a firm grip on their infants.

These observations led primatologist Sarah Hrdy from the University of California, Davis, to suggest that cooperative parenting evolves in primates when, for whatever reason, the mother is unable to cope alone (Mother Nature, Chatto & Windus, 1999). At first her ideas met with some resistance because they challenged people鈥檚 preconceptions about our own species. Throughout most of written history, the care of young children has been regarded as the responsibility of women, in every time and every place. In recent years, however, cultural anthropologists have discovered that this is not always the case.

In two groups of African pygmies, in particular, cooperative parenting is the norm. Among the Efe and the Aka, male and female roles 鈥� whether in hunting, gathering, child-minding, cooking or decision-making 鈥� are virtually interchangeable. When asked who looks after the babies, they reply: 鈥淲e all do.鈥� Barry Hewlett from Washington State University Vancouver, who has studied the Aka for two decades, has found that fathers spend long periods at camp, hold their babies for more than 20 per cent of the day, and are within arms reach for around half the time 鈥� making them the most attentive fathers on the planet. Efe fathers are similarly involved. Might these two small groups present a more faithful picture of our early ancestors than the more macho scenario that has generally been accepted? Reports made by Hewlett and other cultural anthropologists were tantalising, but most experts still required harder evidence.

Primed for parenting

Luckily, that evidence was forthcoming. Two decades ago, primatologist Alan Dixson then at the University of Cambridge showed that marmoset males respond hormonally to their role as father. At first this discovery was met with extreme scepticism, but over the years evidence has accumulated to support the idea that special endocrinological adaptations genetically equip males from several mammalian species for cooperative parenting.

In the company of a pregnant female, the level of the hormone prolactin in the males鈥� blood begins to rise and it continues to increase up to the time of the birth. Prolactin is of ancient origin and in mammals it promotes lactation and fostering behaviour. Clearly, this mechanism serves to prepare male marmosets for a proactive paternal role in childcare. But what about humans? If ancestral fathers had ever been in the habit of behaving in the same way, surely their endocrine system would have been similarly adapted, and traces of this should still be detectable in modern humans.

In 2000, a team of researchers led by Anne Storey from Memorial University in Newfoundland, Canada, revealed that this is indeed the case (Evolution and Human Behavior, vol 21, p 79). Their results were more positive than anyone had expected. In men who were cohabiting with pregnant women, prolactin rose steadily, increasing 20 per cent on average during the three weeks before their partner gave birth. Also, at the time of birth the men鈥檚 testosterone levels dropped dramatically, by up to 33 per cent. What鈥檚 more, it made 鈥渟urprisingly little difference鈥� to the result whether the cohabiting male was the father of the expected child, or knew that he was not, suggesting that the changes are a cooperative adaptation, and not straightforward kin selection.

The big question now is, if men have always had the potential for a prolactin surge, why does it seem to have remained relatively dormant over so much of the world and for so many thousands of years?

The lesson here is not new. It is that while hormones play a key part in determining our actions, their function is often to make certain courses of behaviour possible, rather than inevitable. So prolactin provides, in both males and females, the capacity to respond protectively towards young. But that capacity 鈥� like the capacity to speak 鈥� is conditional on an individual鈥檚 life experience. Someone who has never heard speech will never learn to talk; moreover, even if they do hear speech but only after a certain critical period in their development, they will also never learn to talk. Perhaps the same applies to fostering behaviour, whether in monkeys or people 鈥� it has to be primed. And what primes it could be witnessing loving behaviour towards infants at a critical period in their own development. It has been suggested that is why people who have suffered neglect or abuse in childhood often grow up to be child abusers themselves, even though they may have experienced kinder treatment in the interim.

But even this is not the full story. We also share with the cooperatively parenting monkeys another, more disturbing trait. If a monkey mother perceives that she cannot expect enough social support, she displays a kind of revulsion towards her own infants and is liable to abandon or even kill them. Primatologists interpret this as an adaptation, since the young would be unlikely to survive in any case. Among humans, abandonment or infanticide by mothers has been practised throughout the ages, but it has always been considered aberrant and criminal. Likewise, post-natal depression has often been seen as pathological, with no known cause. In our rapidly changing social environment, perhaps it is time to reassess these conclusions.

We already know that among single parents the incidence of child neglect or child abuse can be significantly decreased even by a single weekly visit from a nurse or social worker. Likewise, working mothers may subconsciously be registering a drop in numbers of helpers ready and willing to lend a hand with the care of their children. The most radical change in western women鈥檚 lives since the second world war has been their entry into the labour market. Most of them welcomed the option of earning a living, but recently it has been changing from an option into an obligation. Meanwhile, as employers become more exigent, support for mothers is dwindling. It has been decimated by smaller families (fewer siblings) greater mobility (more distant grandmothers) and rising living standards (dearth of affordable childminders). Yet the burden of debt makes it harder to contemplate sacrificing the second wage packet.

Perhaps we are approaching the situation that Hrdy pinpointed as the trigger of cooperative parenting in primates 鈥� the point at which the mother finds herself unable to cope alone. Perhaps this helps explain the rise of new man. Clearly the current change in the relationship between babies and their fathers cannot be due to changes in their biological make-up. It has been far too rapid for that. Genetic evolution is very slow, whereas the pace of economic change is rapid and accelerating. But our biological mechanism is sufficiently flexible to adapt to economic change as it has responded, often in the past, to changes of climate and habitat and technology.

Perhaps the truth about human males is that when the need is great enough, the prolactin is in place, ready to come on stream and play its part as of old. Cometh the hour, cometh the new man. And he has never been more welcome.