Why do humans usually have only one child (at a time)?

Question

whereas animals have lots?

Answer 1

some have twins- others have 4, 5,6, 7- when on fertility drugs

Answer 2

Two reasons:

Firstly, human babies are born slightly prematurely. This is bacause upright walking means our narrow pelvises make the birth canal very small and awkward and a baby's head can just about make it out after nine months. A fully developed human brain (adult size) would NEVER make it out, hence we're born completely helpless. As we can't walk or cling yet, and we don't live safely in burrows or anything, human parents must carry their children to safety - and there's a linit to the number that a family group can carry. Also, we have a much, much longer childhood than any other animal - we need to be protected, fed and cared for by our parents. If parents have one every two years, this is possible. If they had a littler of fourteen every two years, it wouldn't be!

Secondly, the aforementioned birth canal problem means that birth is a traumatic event for mother and baby. The number of humans who died giving birth is much higher than animals (in western societies it's better now, thanks to medical intervention). There's also a limit to the SPACE inside the mother, and the amount she can carry as she walks upright. Having 4 babies means they're smaller, weaker and less likely to survive. Before medical intervention although twins were relatively common, more than two was rare and few of them survive. That's why births of four or more are still so noticeable - usually some, if not all, will die.

We're supposed to only have two. Don't believe me? How many breasts does a woman have? Only two! Compared to other animals that have a 'milk line' of four, six etc.

Answer 3

This is a science question, with a real answer, and not a matter of popular opinion. Ask in Biology or Zoology. You will get better answers.

I suspect that the main reason is that we have a longer life expectancy and lower infant mortality, therefore don't need to have a great number of young to replace ourselves.
Another answer might be that women only have two breasts so they can't really support more than 2 kids by themselves.

Answer 4

Our body structure simply doesn't permit it. Since we walk upright, the uterus doesn't expand and contract in the same way. It also has to do with size...humans are not the only animals that have one animal at a time...have you ever seen a horse have more than one foal at a time? Or a cow have more than one calf? Yeah they have twins sometimes but not litters.

Answer 5

Dude you would go insane. They are so much more complicated. Think about it a fawn has to walk in the first 5 mins. of life in order to survive. Animals have to go about their way of life immediately after delivery. Animals are borne with certain survival traits that are used at a very young age. Also, animals have more to ensure the survival of the species.

Answer 6

This is because of the care and time a mother has to look after offspring, the longer the care the less children.. Also could be down to gestation. Of course there are natural exceptions to the rules, it is not unknown for natural quads, quins etc.

Answer 7

some people have 3 babies

but yeah i dont know its wierd,
oh i know its becasue when animals ovulate they release more than one egg , like dogs realease about 15- 20
and only some will get fertalised, but normal human woman normally only release 1 egg a month

Answer 8

because animals have shorter lifespans and are generally used for food or are expendable and ignorant ... where as humans are used to herd and cultivate animals, have enough intelligence to understand that they are exploited and are more difficult to extermnitate for population control

Answer 9

Because of the amount of space available and the amount of maturing still left to do outside the womb.

Answer 10

What exactly are you saying? It's painful enough to have one at a time let alone lots, but you wouldn't know that would you?

Answer 11

Man !
I was there when my little one was born.
I couldn't imagine her popping out a half dozen at a time.
Besides, women only have two ****, other animals have many more.