About 3 out of every 100 births in the United States yields twins. Studying twins is a way for scientists to determine how much of our characteristics are influenced by genetics, since identical twins share nearly 100 percent of their DNA, whereas fraternal twins or normal siblings only share about 50 percent. This list is full of the most interesting twin study findings, and you might be surprised by how significant a role genetics play in determining your future.These interesting twin studies also give us insight into how human beings interact with one another. Vote for what you think is the coolest twin study discovery.
Intelligence Is in Your Genes
It might not surprise you to know that twin studies have taught us that IQ is genetically determined. But it might surprise you that genes also influence how much enjoyment a child gets out of learning, and how motivated they are to succeed in school. Studying twins has led to the conclusion that 62 percent of individual differences in academic achievement can be attributed to genetics.
Most Personality Traits Are Inherited
When scientists compared the personality traits of twins who were raised together against those who were raised apart, they found that the personalities of twins who were raised apart were more similar than they expected. The researchers concluded that personality traits are mostly determined by genetics. Interestingly, the traits most strongly determined by heredity are leadership and obedience to authority.
Gender Identity Is Genetically Determined
Twin boys Bruce and Brian Reimer didn't consent to participating in a case study on gender. Their parents volunteered them, after an accident during what should have been a simple circumcision left Bruce with significant injuries to his genitals. Dr. John Money, who believed that gender was entirely determined by upbringing, suggested that Bruce's parents raise him as a girl.The parents took the doctor's advice, and Bruce became Brenda. The experiment seemed to go just as Dr. Money planned, until Brenda became a teenager. She became depressed and then suicidal. To save her, her parents told her that she had been born a boy, and from that point on, she decided to live life as a man.
Sexual Orientation Is Genetically Influenced
At this point it's generally accepted that people don't choose to be gay, but twin studies have given us the scientific evidence to back that up. In 2001, researchers did a review of multiple twin studies and found that identical twins were more likely to have the same sexual orientation than fraternal twins.