Have you ever caught yourself behaving exactly like your parents, despite having decided that you would never do so? Perhaps you respond to criticism in the same way your father did, worry about the same things your mother worried about, or carry beliefs about success, relationships and life that you never consciously chose.
Where did these patterns come from?
We tend to think of our personality as something uniquely our own. Yet neuroscience suggests that who we become is shaped by a complex interaction of our genes, experiences, environment and relationships. We are not born as finished individuals; we are continually shaped by the world around us.
Your brain is shaped by experience
The PBS NOVA documentary Your Brain: Who's in Control? explores this through the research of neuroscientist Bianca Jones Marlin.
Her work examines how experiences can influence the brain and, under certain circumstances, how their effects may extend across generations.
One particularly fascinating line of research involved mice exposed to the smell of acetophenone, which resembles an almond-like odour. The smell was repeatedly paired with a mild electric shock. Subsequently, the researchers observed changes in the animals' sensitivity to that particular smell. Remarkably, their offspring also showed heightened sensitivity.
The research suggested that certain environmental experiences may influence biological processes associated with gene expression, with effects that can be transmitted across generations in animal models.
This field of research is known as epigenetics. It studies how environmental factors can influence the activity of genes without changing the underlying DNA sequence.
It is important to remember that findings in mice cannot automatically be applied to human beings. The precise extent and mechanisms of transgenerational epigenetic inheritance in humans remain an active area of scientific investigation.
Nevertheless, the broader message is significant: our biological inheritance is not the entire story. Our experiences matter.
We are also shaped by the people around us
The documentary explores another important dimension: our brains are deeply social.
We learn by observing, imitating and interacting with others. Family, friends, teachers, colleagues and the wider society influence how we think, what we value and how we respond to situations.
Consider how a child learns what constitutes acceptable behaviour, how to express anger, how to handle failure or how to treat other people. Much of this learning happens not through formal instruction but through observation and repeated experience.
Our social environment does not merely influence our opinions; it can shape enduring patterns of behaviour.
This is also consistent with contemporary research on brain plasticity: the brain continues to change in response to experience throughout life.
The philosophical connection: Prakriti and Samskara
Indian philosophy has long recognised the influence of nature, conditioning and past impressions on human behaviour.
The Bhagavad Gita, in Chapter 3, Verse 33, observes:
सदृशं चेष्टते स्वस्याः प्रकृतेर्ज्ञानवानपि।
Even a person of knowledge acts according to their own nature (Prakriti).
The concept of Samskara similarly helps us understand how repeated experiences leave impressions that influence our subsequent thoughts, tendencies and behaviour.
These philosophical concepts offer a valuable lens through which to examine the conditioning we acquire through life.
Yet conditioning need not become our destiny. The very awareness that our patterns have been shaped by experience opens the possibility of examining and changing them.
We may not have chosen all the influences that shaped us, but we can begin to become conscious of them and take greater responsibility for who we become.
A question to carry forward
If our thoughts, emotions and behaviour are so deeply influenced by our biology, upbringing and environment, are we really the authors of our actions?
When we make a decision, who is actually making it?
In Part 5: Are You Really the Author of Your Actions?
References and further reading
- NOVA/PBS, Your Brain: Who's in Control? — primary documentary inspiration.
- Dias, B. G. & Ressler, K. J. (2014). Parental Olfactory Experience Influences Behavior and Neural Structure in Subsequent Generations. Nature Neuroscience, 17, 89–96. Read research paper.
- Holuka, C. et al. (2024). Transgenerational Impacts of Early Life Adversity: From Health Determinants, Implications to Epigenetic Consequences. Neuroscience & Biobehavioral Reviews, 164. Read review.
- Bird, A. (2024). Transgenerational Epigenetic Inheritance: A Critical Perspective. Frontiers in Epigenetics and Epigenomics. Read review.
- Bhagavad Gita, 3.33.