With everything that we know about our bodies, our history, and our DNA today, it’s hard to believe there are still things to be discovered about how our world shapes us into the people we are today.

Moshe Szyf, a geneticist, recounts his experiences with discovering how the way we experience life in the beginning can have lasting impacts on our lifestyles as adults.

Studying rats and later monkeys, because studying humans is hard and unethical, Szyf found that by separating newborn animals from their mothers into two groups (one where the baby animal got lots of attention and “love” from its surrogate mother, and one group where the baby was given minimal “love” and attention from its surrogate mother), the dynamic of that animal, the preparedness for life, and the understanding of things like social class were intrinsically present.

But how is this possible?

Moshe Szyf explains his theories, experiments and findings in this compelling TED talk below:

Basically, the hypothesis was that our DNA could be physically changed based on the mother who cared for us — or in this case, the rats and monkeys.

The amount of care rats and monkeys received from their “mothers” during experiments had impacts on the levels of stress, anxiety, obesity, and illness overall. Animals who experienced more attention and care were less likely to develop these conditions, while animals who only received the basic life necessities were more likely to be stressed out and become ill later on in life.

The correlations between the findings in the animals and the likelihood of this occurring in humans seems to be high. One study was referenced about babies that were born after a particularly economic and environmental stressor in a city in Canada that caused the mothers-to-be a great deal of anxiety and worry while they were pregnant. Some 15 years later, these children are experiencing higher levels of disease, anxiety, and obesity.

It’s partly because of our hardwiring DNA that we are all born with, and it’s partly because, Szyf believes, based on how we were raised in our early years. He gives many examples of how children who are brought up to conserve food and eat when they can due to famine or lack of resources to feed a family struggle with obesity and depression later in life because they can’t break the cycle of needing to eat to prepare for a time when there will be no more food.

As more studies are conducted, we might find that our existing DNA can be influenced by our upbringings, our lots in life, and our mothers.