The issue was that in relation to that person's own emotional state, someone had expressed their professional opinion that "your birth parents basically shape you and that not having them available affects all parts of your life and future relationships, for better or worse (generally worse)".
I took issue with this almost immediately. It seemed like an attempt to rely on, or even establish dogma. I'm not going to faff about establishing or claiming credentials. Suffice it to say that:
At one time or another I have been at both the sharp and blunt ends of this type of thinking;
I was adopted at birth, so my Mum and Dad are not my 'birth parents', but I'm VERY sure I know who my Mum and Dad are;
I think about this kind of thing quite a lot, not from the specific 'who are your parents' point of view (a concept which I have never struggled with), but from the 'what forces act upon us' angle.
This is how I see it.
Imagine that each of us stands mentally and emotionally on top of a large ball*. At rest, we would be standing, neatly balanced in the centre, at the top, not particularly aware of any particular slope, or bothered about the nearness of the edge of the ball. Everybody and everything that has an influence on us either tends to push us away from or toward that centre,
which though it feels stable, immediately becomes unstable as soon as you move from it. Move far enough from it that the slope becomes very noticeable, and the emotions associated with that position become quite intense, where small differences in position can make quite a big difference. Go further still, and eventually you can become in danger of actually falling off.
For every individual, not only are the forces acting on them unique, but the size of the ball may vary from person to person, and may even change size for the individual during his or her lifetime. Some
people are less easily pushed than others - arguably because they had sufficient practice at staying in the centre when they were younger, although like any other system its elasticity is finite.
Obviously there will be many similarities between vast numbers of people, and broad classifications may be possible, but the thing I like about this model is that there is room for chaos, and your position on the ball
depends on fluid factors that you have some capacity to resist, particularly if you can ascertain where the biggest pushes and pulls are, and whether they are working towards your centre, or away.
*This is not a ball of significant mass - such as a planet. It has no gravitational effect germane to the illustration, 'down' is always 'down', it does not change relative to the displacement from the starting point.
Apologies to E M Escher for messing about with his pic.