Identical and Fraternal Twins Eggs, Genome.gov, Date Unknown
Nature
Twin studies help support the nature factor of nature vs nurture. Twin studies prove that even without the environment being the same, identical twins raised apart still lead almost identical lives due to their genes being exactly the same. When a mother’s fertilized egg splits to form two identical eggs, the same genes are given to the other twin since both twins were one in the beginning. This is how both twins have the same genes and DNA. Fraternal twins are, from the beginning, two separate eggs and people. They have completely different genes and DNA, and while they can be boy/boy or girl/girl sets, they can also be boy/girl sets too, while identical twins can only be the same gender.
Fraternal Twins Oposite Gender, Wattpad, 2016 Fraternal Twins Same Gender, Incubar, 2020
"Success and failure, credit and blame, in overcoming problems should be calibrated relative to genetic strengths and weaknesses."
~ Robert Plomin
"In essence, the most important thing that parents give to their children is their genes. Your parents' systematic influence on who you are lies within the genes they gave you."
~ Robert Plomin
Personality: Genes or Enviroment, Brainmemind, Date Unknown
How Genes Work, khanacademy, date unknown
Mother and Infant Rhesus Monkeys, PBS Philly, 2017
An experiment done with monkeys adds to the importance of nature and genes. Researchers decided to switch rhesus monkey female babies between moms who had given birth recently. The female infants who had aggressive mothers would also be aggressive even if the adoptive mother was gentle and calm. The female babies were acting the way they were acting because of their genes and nature not because of their environment or nurture.
Another example is that a cuckoo migrates to Africa and back, sings its song, and mates with one of its own species without, as a chick, having ever seen either a parent or sibling. This shows that genes are a big part of some animals' lives since they never got the environment part to teach them. Even for humans, the way we stand, gesture, our posture, the way we walk and talk, has always been thought to have been acquired from family or the modeling of parents. Scientists’ evidence however, has started to suggest that all these traits come from our genes.