Since scientists mapped the human genome in 2003, genetics has played a huge role in how we understand ourselves. People think about genes when worrying about their health. Many believe that genes can explain important aspects of who we are as individuals and the paths we take in life.
Recent studies support this idea. They show that factors such as personality, lifespan, and even how we deal with mental health challenges may be partly influenced by our genes. Even political beliefs might have some genetic link.
Nonetheless, our surroundings and experiences are also important. Education, upbringing, and life events all combine with genetic factors to shape who we become.
Life experiences may affect genes
Scientists in the growing field of epigenetics have found that life experiences may affect genes in ways that can be passed down from generation to generation. This means that what someone goes through during their lifetime might leave a lasting mark on their genes.
For instance, the hunger your Dutch grandmother endured during World War II or the trauma your grandfather experienced as a refugee might still affect your parents’ behavior and even yours.
These experiences don’t just disappear. They can be passed on through changes in genes, as reported by The Guardian.
Scientific studies have shown the possibility that memories can pass between generations through DNA.
The experiences of your ancestors, both good and bad, may play a role in shaping your personality, habits, and fears and your own experiences may do this for your descendants… pic.twitter.com/Uk76YDRJAo
— Robert Kearney (@Robkearney1981) May 24, 2023
Early research in epigenetics was mostly done on animals, including mice. One groundbreaking study, published in Nature Neuroscience in 2014, shocked the scientific community. It was led by Professor Kerry Ressler from Emory University in Georgia.
This study provided a clear look at how behaviors might be influenced by the experiences of past generations. The findings gave new insights into how a person’s actions and genetic memories may be shaped by what their ancestors experiences generations earlier.
In the study, scientists trained mice to fear a cherry-like smell by pairing it with a mild shock. Even though the next two generations never experienced the shocks, they still feared the smell. This happened because the mice’s DNA changed, passing down a fear response to their offspring through altered nerve circuits.
Parental trauma can affect future generations
In 2020, Professor Rachel Yehuda’s study showed that Holocaust survivors passed changes in stress-related genes to their children. These changes, affecting cortisol and immune function, were linked to mental health issues such as anxiety and depression.
Further research revealed epigenetic tags in PTSD-affected soldiers. This research could help diagnose PTSD or identify those more vulnerable prior to deployment.
The findings suggest that our life experiences, including trauma, have the potential to leave lasting marks on our genes, influencing future generations. Our biology and life experiences ae thus more deeply interconnected than previously thought possible.