Is it true that if someone has a baby.....?

Question

with someone that is closely related to their bloodline (for example brother and sister) the baby will be stupid? And if they continue to do this will the next generations progressively keep getting stupider?

Answer 1

Not necessarily. But it does carry significant risks of genetic problems.

We all have a few defective genes simply from random mutations. These defective genes are usually recessive, so the dominant normal gene (that is, the equivalent gene received from the other parent) keeps the genetic code "normal".

A man carrying such a gene has a 50% chance of passing that gene on to one of his offspring (and a 50% chance of passing the normal gene instead.) But if the other parent is unrelated, it would take one h**l of a coincidence if she has the bad gene, too. In virtually every case, both of her copies of this gene are normal, so the child is guaranteed at least one normal gene, and since it is dominant, life goes on.

But if the other parent is a close relative, then there's a decent chance (50% for a sibling) that she has one copy of the bad gene as well. And if their offspring should happen to inherit the bad gene from BOTH parents (25% chance) then that child will have serious genetic problems, which may or may not involve stupidity, but can do nothing but harm.

Answer 2

Well, lowering of intelligence has yet to be observed. However, hemophilia can develop.

Answer 3

When geneticists did experiments on plants, fireflies and certain other insects, the offsprings or 'babies' were weaker , less vibrant and had a lower rate for survival. In humans Marrying 1st cousins itself brings out genetic defects of the gene pool in that family line. These defects include physical defects like cleft-pallette, hare-lip, extra fingers/toes, heart and blood disorders and skin or allergy problems. Mental retardation may also be there if such problems do exist in the gene-pool. A person will only be stupid if naturing and more importantly his nurturing is wrong.  How smart you are has everything to do with how smart YOU want to be. If one is mentally alright, nothing should stand in the way for learning and being smart..despite his genetic inheritance.

Answer 4

Inbreeding makes it more likely that recessive traits will come out.  That could include retardation.  It's not a 100% thing, that every inbred child will be retarded, but it's just an increased likelihood, and it gets more likely with every generation it's repeated.

You ever notice how lab rats are always white with red eyes?  That's the recessive albinism trait coming out due to inbreeding.  My cats had an inbred litter of kittens, 1 was born without a tail, 1 was partial albino, and the other 2 were normal.  They were all as smart as a normal cat though.

Answer 5

No. Not necessarily. BUT......in a family carrying a recessive gene like Hemophilia or Muscular Dystrophy the chances of passing on the defect is very high or almost guaranteed. Plus it's considered socially unacceptable in most developed societies.

I worked with a guy that married his first cousin after many many tests. This was in a high-middle-class family. Their kid is perfectly healthy, smart and normal. But people still whisper about the marriage.

Answer 6

childerens can have many disease.

because some time family members can be career for some disease and it will show up on their next generation.

search on family pidegree charts

Answer 7

Look at some of  what is called hillbillies. They quite often marry cousins and I have met some very dense people who are the products of those unions, and they aren't even brother and sister!