Hunger and tiredness both take a long time to cause a human baby to cry but hunger is often the longer of the 2. Now, yes, for us humans, a hunger cry is important, even though it attracts predators.

But that doesn't mean that my Kepler Bb humanoids, anatomically similar externally, but different internally, couldn't have evolved to not have a hunger cry.

I mean, that species originated on Kepler B#, a nearby planet that is also habitable. And on that planet, with their underground living, since they evolved into the species that they are, they have survived all mass extinctions, even ones that killed really huge animals.

This means that they must have encountered a variety of predators, each with a different affinity towards humanoids and baby cries. This would mean that a general strategy had to evolve when it came to baby cries or they wouldn't have gotten to the futuristic age and settled on Kepler Bb.


What I am proposing is this:

Since hunger cries are often the loudest of all baby cries when the baby is not in pain, this would have the highest potential of attracting predators, even ones that would ignore adult humanoids. This meant trouble in an evolutionary sense. The species could evolve to have less hunger or it could evolve to get rid of the hunger cry. Less hunger would probably mean eventual starvation through the whole species since the majority of this evolution occurred during a "stone age" type era(millions and millions of years). During the stone age, there is no way that you would know when food came. Even time of year is not all that accurate of a sign.

So I figured that instead of being less hungry and the whole species starving to extinction, that there be more time between first hunger cue and crying and quieter hunger cries. This would be less likely to lead to starvation and attract fewer predators.

So over time, as cries get quieter and there is more time in between cries, eventually the hunger cry is gotten rid of completely. Likewise, mothers pay more attention to hunger cues to compensate for this.


Now, here is the big question. Is this plausible? Could evolution favor no hunger cry over a loud hunger cry?

  • $\begingroup$ The complement of "plausible" is "Impossible, very unlikely". Hence any question along the lines of "Is this plausible/possible?" is best answered by posing that opposite question: Is there anything that makes [X] impossible or very unlikely?. In your case the answer is: no, there is nothing that makes the evolution of an absence of a hunger cry impossible or even implausible. So the answer to the original question is: yes, that is plausible. $\endgroup$
    – MichaelK
    Commented Oct 5, 2017 at 7:54

4 Answers 4


There are two ways to do this.

  1. Supply a different form of signaling, the more obvious the better, maybe their babies glow bright purple when they are hungry. Crying is what humans do becasue it is one of the easier forms of signalling babies can already do.

  2. Have the parent not care, maybe they are not K strategists, and instead their offspring are left to fend for themselves. Or maybe they are like crocodiles and the parents provide care but not necessarily food, the young feed themselves and the adults provide protection. If they babies can feed themselves signaling is unnecessary.

Basically that's it. Hunger will exist and babies can't feed themselves so they need to be able to signal when they need to be fed. So you either need to have a way for the baby to feed itself or you need a different signal it can use you tell the mother it is hungry.

Predator preferences won't do much becasue either human can fight the predators off consistently, in which case the cries are not detrimental enough to risk loosing and have offspring become malnourished, or they can't fight them off in which case they would not survive anyway. Humans are too big and obvious and have too much calorie demands to hide a large segment of the population without protection.

  • $\begingroup$ This is the strongest answer (so far) in my opinion because of point #1 -- the most likely reason to not have a hunger cry, assuming the parents need to feed the baby, is that they signal some other way. It's a cave... maybe the baby glows in the dark and gets brighter when hungry? $\endgroup$
    – SRM
    Commented Apr 10, 2017 at 5:51

Humans have encountered:

a variety of predators, each with a different affinity towards humanoids and baby cries.

And yet, we still have a hunger cry. Why?

It's because the benefit of the hunger cry (getting fed in a timely manner) outweighed the cost of a hunger cry (attracting predators).

If you want to eliminate the hunger cry you are going to have to make it far more costly for babies to survive (and have mothers more willing to abandon any that do early in evolution, which goes against the motherly instinct of protecting offspring). Or you are going to have to have babies that don't expect to be fed by their parents. Offspring that are NOT helpless and dependant on their mothers don't have a cry, but those that are DO.

Mothers are more likely to keep their babies fed to keep them quiet, if that's a factor in the survival of the WHOLE tribe. But human mothers and tribes tend to protect babies and give them more resources for just this reason. Unless the cost of the hunger cry results in the death of many, many, many generations of babies the answer is no, evolution won't. If the entire tribe is wiped out because of one baby or because mothers leave their babies alone a bunch, then...yes, evolution will.

Consider the kitten. They are relatively helpless and they cry for food. This puts them at risk for predators because of it, but it benefits them enough with their mothers that they still do.

If your kids have a non-verbal signal that mothers will "listen" to then the answer is yes.

  • $\begingroup$ "If you want to eliminate the hunger cry...". OP is not looking to eliminate an existing hunger cry. They are looking to see if it is possible/plausible that it did not evolve in the first place. $\endgroup$
    – MichaelK
    Commented Oct 5, 2017 at 7:57
  • $\begingroup$ @MichaelK Read the question again. I am quoting "The species could evolve to have less hunger or it could evolve to get rid of the hunger cry." This implies that the species early in their evolution might have had one. Thanks for the -2. $\endgroup$ Commented Oct 5, 2017 at 20:39

A lot of things are possible with sufficient evolutionary pressure.

What makes this difficult is that a baby does not cry because the baby is hungry. The baby doesn't know what hunger is. It has no concept of hunger. The baby cries because some of the nerves attached to its brain are going off like fireworks (because they are detecting an evolutionary unpopular set of chemical signals we call hunger). It's not that hunger cries are the loudest cry a baby makes when not in pain. It's a cry because the baby is in pain and it doesn't yet understand why! It's crying because evolution is giving the baby a big kick in the pants saying "you better speak up now, because there's something wrong. Until you understand what that thing is, you better scream."

The easy solution, of course, is to give the Kepler Bb babies a sense of hunger from birth. Wire the concept of being hungry into their brain at a far lower level than we have it. Instead, the baby can give off some similarly hard-to-ignore but quiter signal. Perhaps their eyes roll back in their heads. That doesn't waste much energy, and it will definitely get the attention of a concerned parent.

Of course, you could also take the exotic approach. In Rendezvous with Rama, Clarke wrote in the Octospiders which are truly a fascinating race. Almong their many unusual tendencies, one of them is that Octospiders are not born with an awareness of how hungry or full they are. Infant octospiders literally must be taught how to detect their own hunger, or they will die of hunger with food all around them, simply because they aren't aware they need to eat.

  • $\begingroup$ Hunger is a basic emotional response, like pain or pleasure, the child needs no concept of hunger to experience hunger as a separate thing from pain. Babies do not cry when they are hungry becasue they are in pain. Other things babies do when hungry is suckle, which they will not do when not hungry, or say, in pain. $\endgroup$
    – John
    Commented Apr 10, 2017 at 3:48
  • $\begingroup$ @John Interesting. Our child is more than happy to cry without suckling when she's hungry, and she's more than happy to resolve her pain (such as from falling down) with suckling! And let me tell you, there's some serious learning that goes on in learning to suckle. For being so natural it sure takes a kid a while to get the hang of it! $\endgroup$
    – Cort Ammon
    Commented Apr 10, 2017 at 4:10
  • $\begingroup$ What makes you think she is hungry if she is not suckling? And what makes you think suckling is being used to resolve pain, it is possible for a child to be hungry and in mild pain at the same time. But yes babies are prone to experimentation, but that does not mean hunger somehow translates to pain for a child. $\endgroup$
    – John
    Commented Apr 10, 2017 at 4:18
  • $\begingroup$ @John We thought she was hungry because the nurse at the hospital let us know that she should be hungry at that time and gave my wife a few tips about how to get our child to latch because they couldn't let us leave until it was clear that our child had figured out how to feed properly and learned that that was a way to pacify that cause of her crying. As for the latter case, she can cry because she hurts her leg, but comfort herself by sucking on a pacifier... did you not give your kids a pacifier? $\endgroup$
    – Cort Ammon
    Commented Apr 10, 2017 at 5:49
  • $\begingroup$ My side of the family has a history of dental problems, so no we didn't. As for latching I was not thinking of the first few week where the child is still learning how to control its own muscles, and yes I recognize that special cases do exist. And distraction works on mild pain no matter what age you are, If someone distracts a child with a skinned knee by taking them out for ice cream, that doesn't mean the kid is confusing hunger with pain. $\endgroup$
    – John
    Commented Apr 10, 2017 at 13:40

Anglo babies cry a lot. In other cultures babies cry much less. American indian babies are able to cry of course but compared to anglos these babies are spooky quiet. I have seen it and I do not know why it is. They still watch you and wiggle and do all the other baby stuff. Reading on the web you find a lot of BS. I suspect the following might be.

from http://www.indianreader.com/indian.html

Let us begin with the beginning. From time before memory, Indian babies have been taught not to cry within days of their birth. If there was a hunt in progress, if there were hostile neighbors to avoid, or if the Seventh Cavalry was stalking, the cry of a baby could place the survival of the group in jeopardy. Whether training babies not to cry was universal among Indian groups, or to what extent it is still practiced is unclear, but the method is simple enough: when the newborn begins to cry, place the hand over the nose. The mouth now must be used for breathing, not vocalizing. Take the hand away. If the baby cries, repeat. The method teaches quickly. From now on, communication from the baby will be a small whimper, not the piercing wail we often hear today. This sounds like a simple trick, but is it really?

Freedman tested a group of racially-different babies for this "defense reaction" and found that while the Chinese and Navajo babies accepted the cloth pressed to their noses and lay back breathing through their mouths, Anglo and Black babies fought by swiping at it and struggling to get away. In another study, a group of Anglo mothers who wanted to raise their babies on Navajo cradle boards gave up in failure: apparently their babies howled so persistently that they were off the tightly-wrapped board in a matter of a few weeks. Just how scientifically valid these findings are remain to be seen. But, if the inference is obvious, so are the long-term implications as those babies grow up.

Trying to find links for the "indian babies don't cry premise" I ran into a lot of stuff about African babies not crying. Also about Indian babies crying a lot; these turned out to be the subcontinental Indians.

It is totally plausible to have babies who are constitutionally just very quiet.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .