Why does it take so long for a new born human baby to reach adulthood?

Question

I already know that humans have one of the longest lifespans compared with other animals.

A newborn baby takes 18 years to grow and reach maturity. Some animals, on the other hand, takes only a year or several months to reach their adulthood.

Answer 1

Due to primates maternal instincts it's much less beneficial to hedge your bets with a large litter, instead having a single child and taking care of it to maturity is the efficient option.

Answer 2

One of the reasons is that our brains cannot be too large, because if they were, our heads would be too big to fit through our mothers; pelvises.  Thus, the brain must do a lot of growth and development after birth.  

As to 18 being the age of maturity, it was not considered that in earlier ages.  In the middle ages, many people got married at 14 or so.  The age of what we consider maturity has been getting older, because of the increasing technology - people think they need more training before they go into the working world, and in many ways, students are not considered mature.

Answer 3

genetics determines everything. Though turtles can live to be over 200 and birds can live to be 80. So maybe its just a question we will never full understand why.

Answer 4

It is just HUMAN nature not ANIMAL nature. That was just the way we were made.

Answer 5

And how soon after do those other species die?

Answer 6

not sure but I know, some never do

Answer 7

Nobody knows for sure. We also are the only species that has delayed growth spurt after birth. Most animals just have a growth spurt right away but we take a while to mature a bit and then have a growth spurt. And as we get healthier our growth spurts have been getting later and longer. Very strange.

Answer 8

Did you ever consider that is not the only difference?  Try a comparison with elephants.  They have a similar society, maturity rate and life span.

I believe it has some to do with the way our society works as well as the need for the brain to properly develop.  The human brain is still developing into the twenties...though some show no evidence.  Actual maturity isn't until somewhere in the twenties.  Being physically able to reproduce does not and should not imply maturity.

Answer 9

You think an eighteen year old is mature? Think again.

Answer 10

Sexual maturity is like 13-ish, which is the 'maturity' we should use in this case because we're talking about sexual maturity in animals when we say they're 'mature.'  For most of human history the average lifespan was only 25-30, so we spent about 12-15 years reaching sexual maturity, we reproduced, then we spent 12-15 years raising our offspring to sexual maturity, then we died.

Even so, that's still a pretty long time.  Probably because of the amount of energy required to develop an intelligent brain, and a certain minimum lifetime for there to be a payoff for intelligence (time to learn.)  Other species with long maturity rates are also intelligent, like other apes or elephants.

It's also relevant that a human newborn is less physically developed than most animal newborns, just because a fully developed human with a big head for a big brain would be impossible to give birth to.  So we give birth to our young prematurely, so to speak, and allow them to continue development outside the womb.

Answer 11

We have such a long life span it takes us a long time to mature and have the intelligence that goes with adulthood.

Answer 12

These people are awful at biology. They might as well say: "Oh, God, meant it like that, so don't ask!" LMAO

It is because we are complex animals, humans need years until the endocrine and pituary glands of the hypothalamus in the brain are mature enough to initiate puberty via the release of hormones. That is why, and that is my final answer.

Answer 13

because we suck.