Question

Fraternal twins are no more genetically similar that non-twin siblings, yet the IQs of fraternal twins are more strongly correlated that those of non-twin brothers and sisters?

What is the difference?

Answer 1

Fraternal twins does not much corelated with same intelligence and IQ level . Their intelligence or IQ can differ just as much as between two siblings because they don't show the same DNA as like identical twin do . So we can't say that intelligence strongly corelated to each other . But it also happens that there is not much difference between two farternal twins in intelligence in some cases.

step-2

With fraternal twins , we see completely different picture . Since they come from diffrent eggs . They are as much difference as two siblings would be. One of them could be boy where another can be girl .even their intelligence can also be diffrent . Because they are not below from same DNA. They are developed from 2 separate egg and sperms. They are may or may not look alike or act similar . They both have certain unique needs , interest and capablities .