Will nature or nurture play a bigger role in your baby’s developing personality? It’s a question that philosophers and scientists have argued about for centuries. There’s still no simple answer. It’s complicated.
Yes, your baby will probably inherit some familial traits. She may have the freckles that are common in your mom’s family or also suffer from allergies like your dad does. He may share your grandfather’s talent for long distance running or your grandmother’s musical talents, but not everything is determined by genetics.
While genetics play a significant role in determining health risks and shaping personalities, it’s more complicated than that.
The History of Nature vs Nurture
Long before science understood the exact workings of genetics, farmers and herders noticed that breeding certain pairs of animals would increase the likelihood of specific physical traits being passed on. They probably assumed that humans had a similar chance of inheriting one physical trait or another. However, there was some disagreement about whether a child’s personality was inherited or was shaped by experiences.
The Greek physician and philosopher Galen (129 AD – 216 D) thought temperament was inherited and those ideas remained popular until the 17th century. English philosopher and physician John Locke (1632 to 1704) argued that a child was born a blank slate and character was solely determined by external influences, such as having the proper education and a moral upbringing.
Science comes to favor DNA
As scientists began to learn more about genetics in the 20th century, the idea that personalities were determined by DNA grew in popularity. Those less than desirable personality traits could be blamed on DNA. But, in fact, it’s not that simple. Certain physical or personality traits can definitely be inherited but the environment a child is raised in also has a moderating effect on those traits.
For example, DNA plays a role in determining intelligence but a 2003 Swedish study compared the I.Q. of identical twins who were reared separately, finding that twins raised in an middle class homes on average had a higher I.Q. than their siblings raised in poor households. Both twins may have been equally gifted but one had the advantage of well-to-do educated parents who had the time and resources to encourage learning. A twin with access to resources has an advantage when taking a test.
Why there have been so many twin studies
Scientists have done multiple studies of twins in an attempt to answer the nature vs nurture debate. Identical twins share 100 percent of the same genes and usually grow up together. Fraternal twins share only half of the same genes, but are also usually raised in the same environment. By these observing different sets of identical and fraternal twins, scientists hoped to determine whether identical twins shared more of the same personality traits than fraternal twins. Other twin studies documented the personality traits that identical twins shared when raised in a different environment.
Studies such as those done by the Minnesota Center for Twin and Family Research found that identical twins who were reared in different households still often had surprisingly similar personalities and interests. Never having met each other, these identical twins made similar choices in the homes they bought, the cars they drove, and even what they named their pets. The studied confirmed that there is a genetic basis for personality traits.
Inherited personality traits affect how your child will live and interact with others, but, conversely, life experiences, such as a traumatic event, can also switch genes on or off and this genetic change can be passed onto future generations. The field of research which studies this is called epigenetics.
As an illustration of how complicated the relationship between nature and nurture can get, let’s say a child is very energetic. His parents are reserved and disapprove of his high energy Because of their own personality traits and lack of experience in dealing with energetic children, the parents may not know fitting channels for his energy—such as athletics—and the child may grow up thinking he lacks self control. This poor self-image may be mirrored by those he encounters. However, a high energy child, born to high energy parents—or even parents who help him channel that energy into something productive—will see himself and the world in a different way. As a result, the world may treat that child differently.
While nature may dictate some of your baby’s personality traits, DNA is not destiny. Nurture can influence how those genes are expressed. What your baby inherits may not be under your control but how you care for and nurture him is.