It’s only been in the past 15 years or so, that certain scientific discoveries have changed our minds about how we can change our minds. The old longstanding belief was that our brains stopped growing at around age 25, and remained essentially unchanged throughout the rest of our lives. Well except in negative ways, such as with injury, drugs, dementia, or old age. Though it is completely true that the developmental phase of our growth ends around our mid-20’s, it’s now understood that our minds continue to grow throughout our whole adulthood, just by a different mechanism – a more deliberate process of growth through learning. Both types of personal growth, developmental and learning, have implications on our mental healthiness. Especially when we are talking about our developmental growth (from conception to the end of our biological adolescence), optimal experiences produce optimal outcomes. Less than favorable conditions leave room for improvement. But as we previously learned in the How Do We Grow series, we can all continue to grow at any stage in life to overcome what may have worked against us previously. Learning about the factors that affect us early in life can help us understand where we are today by providing a sense of our strengths as well as the areas of needed growth. These insights help us to set meaningful goals that can motivate us to course-correct back towards optimal healthiness.
The first type of personal growth, developmental growth, is driven by biological factors programmed into our DNA interacting with the environment in which we live. This starts at the moment of our conception when we inherit our genes from our parents, 50% from mom and 50% from dad, creating the unique combination that makes up our own individual genetic code. Then, in a highly predictable and consistent fashion, there is a preprogrammed timeline of change that starts with that first single-cell zygote dividing into two identical cells…then four, then eight and so on until those cells become two layers of differentiated cell types. This process continues with more differentiation and replication, and the familiar aspects of our human form, both mind and body, start to take shape while in the womb. If the environment in which we develop remains favorable, i.e. mom’s needs are met and therefore this growing human’s needs are met too, then things go as well as expected. If there are problems, in the DNA or the environment, then that’s when complications arise. The interaction between nature and nurture is already relevant to this stage of life. I remember before my first child was born that in our early visits to the OB, measurements of his length and head size could pinpoint down to the day how far along he was in his development and provided reassurance that he and my wife were doing well. Going into the second trimester, a higher resolution ultrasound examination allowed the doctor to measure his head circumference, femur length, nuchal translucency, and see the chambers of his heart pumping. All would reliably tell us that his body and mind were maturing at the expected pace, again reinforcing that my wife was taking care of his needs by taking care of hers.
This is also true after babies are born where under favorable conditions, now relating to having a secure attachment to caretakers, having physiologic needs met, and getting reinforcing and validating feedback from the world, healthy children grow at a generally consistent pace from child to child. Instead of indirect and interpretive assessment through ultrasound, we can now interact directly with children and observe developmental milestones. Some more familiar examples may include being able to walk by the first birthday, being able to use two words by the second, and using the toilet by three. If we’ve had an environmentally favorable childhood then we would have met our maximum human potential (at least for this stage in life), but if our childhood has been less than perfect, ranging from severe neglect to something more subtle like being a middle child who didn’t quite get the attention that your older or younger siblings got, then some aspects of development – physical, emotional, social, may be delayed or remain in a state of stagnation or dysfunction. And though none of us can recall the details of the first couple of years of life, it is during this time that we “remember” through a different mechanism (implicit memories stored and coordinated through our amygdala) and these types of memories have huge influence over the development of our brain’s prefrontal lobe functioning. Why is this important? Because it is the functions of our prefrontal cortex that make us uniquely human. Our emotional regulation, impulse control, self-awareness, empathy, moral sense, highest critical thinking, and intuition – all are abilities that originate and are coordinated in this region of the brain. The first two years of life lay the foundation for these lifelong abilities.
These early life experiences also strongly shape the meaningful outcomes for our whole life. The Grant Study, a remarkable 75-year longitudinal study of 268 physically and mentally healthy Harvard college sophomores from the classes of 1939–1944 has shown that “warm relationships” (with your mother and father in particular) predict a whole range of positive outcomes, including happiness, earning potential, low levels of anxiety, how much you enjoy your vacations and your life satisfaction. In the words of the primary investigator, Psychiatrist George Vaillant, “warmth of relationships throughout life have the greatest positive impact on life satisfaction.” He also summarizes the cumulative data by saying: “Happiness is love. Full stop.” Other research in Attachment Psychology have shown positive links with happiness, longevity, physical and mental health.
As we continue through our childhood, we take in the world through our senses and through an absorption of the states of those around us. This mechanism of experiential mirroring is not completely understood, but is facilitated by “mirror neurons” which reside in different regions of our brain. If an adult sticks their tongue out at a newborn baby, the baby’s mind creates a map of what neurons were used in the adult’s brain, and then recruits the same circuits in their own brain to replicate the movement, sticking their tongue out for the first time. This is done without words or instructions, but instead with actual mind-reading. Again, how exactly this process works is not known, but it absolutely happens and serves as the primary mechanism as to how children learn. This emphasizes the importance of having positive relationships early in life because children replicate the mental states of those around them and repeat those states in their own mind. This explains why parents who are emotionally regulated and attuned with their children can facilitate the same positive state in their kids, and why emotionally dysregulated parents can cause their kids to feel distress.
If that sounds overwhelming because it suggests that we all need to be perfect before we have children and need to be perfect while in the presence of children, that’s not the case. Because as children, we are way less judgmental about our own thinking and therefore have a mental flexibility that allows us to make ongoing adaptations when things aren’t quite right – without pausing to criticize ourselves (or others) for being wrong. For example, as a child learns to use words to communicate, they may start off by saying “me go.” Over time, as they get feedback from the outside world, future iterations of the statement get adjusted – “me goed,” or “me went,” or “I goed” then eventually to “I went.” Again, all learned naturally without instruction or teaching of what is “right.” Without being judgmental, children are more naturally forgiving when things aren’t going quite right. Forgiving of themselves and forgiving of their caregivers. As they form longitudinal memories, it is the larger narrative that shapes their beliefs and understanding, not each incident or iteration.
In practice, when we look at this time in life from a developmental perspective, we the adults can also learn to be less judgmental. In the same way that you wouldn’t feel the need to tell a one-year old taking their first steps that they are “doing it wrong,” there’s many other aspects of normal human development that are just right for their age. “Me goed” is developmentally appropriate for a two year old, it’s only “wrong” for an adult. In terms of doing what they are capable of and for the purpose of the developing ability, in this case language, it’s just right. This less judgmental perspective also applies when we reflect on our own life, looking at our younger selves. Certain conclusions that were made about the world or ourselves when we were young may have been the best we could do at the time – developmentally appropriate, “just right” for what we knew and were capable of. It’s unfair to expect our younger selves to have had adult perspectives, tools, insights or motivations. When working with individuals in my practice, sometimes understanding this truth helps a person finally grow past their own negative view of themselves, especially as they too look at the larger narrative of their own life, also seeing the way their life story moves on, not perseverating on what was “wrong” during a certain time. This is also why I encourage us to remember that we’ve all been through a developmental growth period, and recognize the positives and limits of this time in life.
Looking at the big picture, it becomes clear that our individual developmental path is a product of what resides in our genes and the environment in which we grow. So rather than nature versus nurture, it’s really nature and nurture, for better or for worse. That being said, there’s only one part of this equation that we have influence over. Here’s a clue – we didn’t pick our DNA. This brings us to the other way in which we grow – through learning. In the next part of this series, we’ll talk about how our better understanding of neuroplasticity gives us all the opportunity to make ourselves better and healthier – regardless of where our developmental growth has taken us.
Mental Healthiness 
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