Why do human newborns make so much noise?

Newborn animals know that when mommy is away, they need to be very, very quiet–it’s a matter of life or death. Fawns sink as low to the ground as they can, lying motionless, trying to avoid detection. Baby birds huddle together quietly, saving their noisemaking until momma comes home. Even lion cubs know that being quiet and undetectable is a life-saving issue.

So–why is it human newborns (let’s say 0-3mos) cry so much? In more primitive times, wouldn’t that signal every predator in town to come get an easy meal? Unlike the fawn or the cubs (or really, all other infant animals), a human baby can’t effectively run from danger for years…we’re pretty helpless for the first several months.

Why draw attention to that fact?? Wouldn’t it make sense, Darwinian-wise, that noisy babies would get culled from the gene pool? How did this mega-WAH! factor become a successful genetic attribute?

Human beings don’t operate like deer, or many other animals who’s babies hide and stay silent. Humans are social animals who live in groups. In ancient times, the baby would’ve been surrounded by it’s mother and father, along with other adults in the group. Not an easy target for a predator.

Most newborn babies don’t cry all that much, really. Only (like baby birds) when they’re hungry, or when wet (which presumably they wouldn’t be “naturally”, as diapers aren’t natural) or, like all cubs, when scared or in danger.

Colic doesn’t set in until about 2 or 4 weeks old, and in only 20% of babies, and is much less common in Attachment Parenting, which is likely the “natural” way to do it.

Humans are social creatures who give birth to exceedingly immature infants. They’re more like joeys than wolf cubs. Wolf cubs, not too long after birth, can at least run away from danger. Joeys need to be held all the time in Mama’s pouch. Similarly, human babies need to be held or carried most or all of the time for optimal safety, feeding and neurological development. We formed “packs” so that other people could do the hunting and gathering while a few people stay behind with the babies, scaring off any hungry predators arroused by the babies’ cries.

Conversely, other animal babies are not so quiet as you seem to think. I hear racoon kits calling for their mamas all the time. Wolf cubs are noisy in their den, as well. Birds - oy! - the baby birds outside my window won’t shut up, whether their parents are around or not. Fawns, I think, are too far removed from hunter types to be comparable. Predators and prey live differently and have developed different behavioral strategies.

Humans ARE predators, as well as pack animals. In the wild, ape babies are rarely left alone and are always well guarded. It is therefore not disadvantageous for a newborn primate to be noisy, as long as there are adults to guard it until it can defend itself. And as long as it’s not a detriment to later reproduction, crying is not a trait that needs to be weeded out.

I gotta say, my baby (3 months old now) wasn’t colicky at all, but when they’re teeny they don’t cry for as specific a reason as hunger. They cry when they’re hungry, yes, but interestingly very few babies cry due to dirty diapers (cite–Dr. Sears The Baby Book and What to Expect the First Year–in fact, those are my cites for the rest of the facts in this post, unless otherwise noted). Yes, they cry when hungry, but they also just…cry. Colic is defined usually by the rule of 3s–three hours or more of crying (yiiiiiiiiiiiiiikes), 3 or more days a week, 3 or more weeks in a row.

We follow the attachment parenting model, but RuffLlama still would cry (much less now that he’s older). One book–Happiest Baby on the Block–seeks to teach parents how to limit crying, and it poses the same question as the thread title–why cry so much? (HBONTB also states we are born still fetuses–that there is a 4th "tri"mester that isn’t possible in the womb due to head and baby body size, so we have to live out those three months externally.)

I thought about the social aspect of it, and think of infant primates as the obvious, most similar comparison. Yet even they make no where near as much noise as their human relatives–it just seems odd. Yes, baby gets protection from the group, but still it would seem that hours of loud crying still would alert every predator in town to come and wait for the group to have an inattentive moment.

Because human babies are so much more dependant on their parents than most other animals. Even without predators, an abandoned human baby is going to die. The crying is to make sure they won’t be abandoned. A baby by itself might be an easy meal, but a baby with its mother is no easier a meal than the mother is.

I am not a primatologist, but I wonder if you are, either. I think the easiest explanation is that you over-estimate the amount of time an average human baby cries (and I understand why - 3 minutes seems like an hour!, but “hours of loud crying” is not normal, unless we’re talking colic), and underestimate how much noise other predator infants make.

Kittens certainly cry when prematurely separated from their mothers, and the all night crying of a puppy during the first night with a new owner, and away from Mom and the littermates, is well known to just about everyone who has ever owned a dog.

I’ve heard similar reasons to what Chronos said. (Reading up on it as I’ll have my own bundle of noise to deal with soon enough.) Best guess seems to be that some baby cried louder than others and had its needs met before other, quieter babies and therefore survived over those. Get a bunch of those and allow natural selection to do its thing and we’ve got babies who can’t communicate particularly well, but can at least sound a warning claxon.

And as others have said, while a quiet baby may work best for some animals, the loud human babies would have taken over once our ancestors started living in organized packs, so other predators became less of an issue.

Predators are like criminals – they go for the easy kill. They’re not going to wait around, passing up easier prey, to hang around a camp filled with fully-grown human adults armed with spears and fire, just on the off-chance somebody will leave a helpless infant alone that they can snatch. They’ll go off somewhere and try to pick off a sick deer or a rabbit with an injured leg or something. All the predators in the area will be wary of humans anyway – we’re big, we’re smelly, we’re noisy, we have sticks that poke, we hurl rocks, we travel in packs, we carry around fire. Not ideal prey animals. Even predators as big as lions and tigers rarely go after humans, and when they do, they tend to be older or injured animals that have resorted to hunting humans out of desperation.

If you’ve ever taken care of an infant, you’ll know that a babies cry is extremely irritating to adults. Short of killing the little sucker, the only way of dealing with it is to respond to its needs or wants.

I suspect that the reason you don’t hear other infant mammals utilizing the same technique to such a degree is that humans are not hard wired for maternal care to the same degree as other mammals. We’ve developed a degree of free choice. There’s no way mother is going to wake up and feed the little tyke if it doesn’t cry.

That and I would suggest the infant homo sapiens are high maintenance due to requirements for brain development and the lack of a fur coat.

Babies cry mainly because there is no disadvantage in doing so. Humans and their predecessors have been at or near the top of the food chain for a very long time.

A baby that cries gets attention. Attention keeps a baby alive. There’s a selective advantage in crying and no disadvantage.

I would agree, too, that it’s strange to claim other animal babies are quiet. Kittens absolutely are not quiet when Mommy’s away; I’ve had more than a few litters around and they’ll scream as loud as their little bodies are able. The only reason a human baby is louder is that it’s bigger.

I might add the following.

Isn’t it true that the first thing an emerging fetus does upon breathing is cry?

I’m not sure that is the case with other mammals.

No, it’s not true.

A baby might cry when it’s born, but not all of them do. Many, if not most, don’t cry until the nurse roughs 'em up a bit with a towel while cleaning off the amniotic fluid and other gunk off their skin. The nurse WANTS to hear a cry, because it lets her know that the little tyke is breathing good deep breaths into the lungs.

Some babies cry spontaneously if they’re brought into bright artificial lights or placed on a hard, cold metal scale. But a baby brought out slowly and gently with no loud voices into a reasonably warm and dimly lit room and placed on Mama’s warm belly (ie, a “natural”, as opposed to hospital, birth) won’t cry at all, most of the time.

Mine sure did, although he was in a warm, dimly lit room and placed immediately on my bare skin afterwards. Wow, did his lungs work! He had nearly an hour of skin-to-skin contact and bonding (and immediate attempts at suckling), and he still was peeved for a while.

But, to be fair, they had suctioned his nose of amniotic fluid, and babies HATE that. I also didn’t use any pain meds, which typically sedate the infant a bit. Since he was without sedation, he came into this world fully aware…and PISSED. “WTF?!? I was warm, dark, and cozy floating around…NOW it’s [comparitively] bright, cool, and soooo…OPEN! And damn that gravity…”

Yeah, I’m no primatologist (shocking, I know); I guess I’m just connecting what I read in HBOTB with what I think I’ve observed in various wildlife documentaries and such. I know kittens and baby birds and whatnot can be quite loud, but it seems an infant’s shriek wins the decibel-to-weight ratio.

Screaming baby gets attention; makes sense. Dammit. (She says after taking a too freaking long to lull her over-tired infant to sleep…WHY does he fight sleep so much?? …but that’s another question.) :wink:

The crying because they’re trying to promote a change in their environment. The baby might be hungry, thirsty, wet, cold, hot, have an itch it can’t reach, bored, it’s always one damned thing after another. They usually only cry until they achieve the change.