This topic has been the subject of some debate on the forums for some time.
Now, it does need to be borne in mind that just as genes do not control our destiny, neither does our upbringing. However it is influential and this needs to be understood.
I will not go into detail of the evidence- but it is searchable given the basic information presented here. The book I am quoting from is very heavlly referenced.
A good summary of the evidence is found in the book "Affect Regulation and The Origin of the Self", by the psychiatrist Alan Schore.
I quote from the summary of chapter 21.
"The Onset of Dual Component Orbitofrontal Mature Structure and Adaptive Function"
An anatomical maturation of the connections between limbic areas in the frontal lobe (ie anterior cingulate gyrus)and other areas of the cortex occurs in the middle of the second year.In te same period permanent interconnections between the frontolimbic cortex and subcortical limbic sites are also established. The experience dependent imprinting of these circuits is influences by the child's affective experiences in the dyadic relationship (between infant and primary caregiver) during the late practicing period (once the infant starts to move and has to find the balance between exploration ad safety). By the end of the critical period, a socio-affective stimulation dependent parcellation process has etched the ventral and lateral tegmental limbic circuits into orbito frontal regions. This differentiated, dual circuit system is capable of an ontogenetic progression, the generation of a more efficient delayed response which supports symbolic representational capacity and a more complex emotional regulation.
In short we are talking about the foundations of he circuits that Russell Barkely draws our attention to here:
The main aim of parenting at this point is to try and achieve a balanced tension between exploration and safety and ensure that the infant experiences enough tension and frustration to stimulate growth and tolerance of these emotions, without being too continually frustrated or too continually indulged. If the outcome is for instance a predominant experience of anxiety or abandonment then he nervous system will develop to accept these states as normal- and that will set the scene for future experiences.
Most parenting is "good enough" but what happens if there is a family crisis like maternal depression, death of a partner, marital discord or a financial crisis? How do thing go if you just get a really cranky infant? (see my post re upper cervical injuries- these are cranky infants. (My mother is still telling me about me!)
So you can look at this information and understand that while ADHD is a neurodevelopmental disorder, there can be all sorts of causes of neurodevelopmental disorders.
Bad foundations of development set the scene for a child whose emotional regulation problems set him up for future negative experiences at school- and the problem compounds.
Current understandings of neuroplasticity though do make it clear that this can be remedied - the solution for a neurodevelopmental disorder is to set the scene to allow more development.(but that is another topic)
The point of this post is not to make any of us feel that we are inadequate as parents nor that our parents have been inadequate.
(After all, virtually all of us are doing the best we can with the materials and information we at hand. Many of us have had our own difficulties and our own imperfections that leave us struggling to be truly effective.
The point of this post is to stress that there is very solid evidence that points to the importance of the attachment relationship in helping a child to mature effectively.
Once we know this to be true, it becomes clear that one of the most useful things we can do to help others and to improve our society, and the emotional stability of the next generation is to support the parents of young children so that social settings are directed to make the well being of the next generation our primary focus. Not profit or wealth, the ability of our children to grow up to reach their potential.
This cannot happen when most of parental time is taken up by working very long hours and we are all so busy we do not know our neghbours well enough to be friendly. So part of the work becomes learning to stand up for the idea of a living wage and to stand up to employers who are not family friendly. That is a big jo.
We have to start this process closest to home- with our own families and with our friends, but the beneficial effects of this approach will continue to ripple out as we all get better at it.