The infant is afraid to lose his mother physically (no "mother permanence") as well as emotionally (will she be angry at this new found autonomy?). He goes away a step or two and runs back to receive the mother's reassurance that she still loves him and that she is still there. The tearing up of one's self into my SELF and the OUTSIDE WORLD is an unimaginable feat. It is equivalent to discovering irrefutable proof that the universe is an illusion created by the brain or that our brain belongs to a universal pool and not to us, or that we are God (the child discovers that he is not God, it is a discovery of the same magnitude). The child's mind is shredded to pieces: some pieces are still HE and others are NOT HE (=the outside world). This is an absolutely psychedelic experience (and the root of all psychoses, probably).
If not managed properly, if disturbed in some way (mainly emotionally), if the separation - individuation process goes awry, it could result in serious psychopathologies. There are grounds to believe that several personality disorders (Narcissistic and Borderline) can be traced to a disturbance in this process in early childhood.
Then, of course, there is the on-going traumatic process that we call "life".
Parenting - The Irrational Vocation
By: Dr. Sam Vaknin
There are some grounds to assume that a cognitive dissonance is involved in feeling that children are more a satisfaction than a nuisance. Why do people bother with parenting? It is time consuming, exhausting, strains otherwise pleasurable and tranquil relationships to their limits. Still, humanity keeps at it: breeding.
It is the easiest to resort to Nature. After all, all living species breed and most of them parent. We are, all taken into consideration, animals and, therefore, subject to the same instinctive behaviour patterns. There is no point in looking for a reason: survival itself (whether of the gene pool or, on a higher level, of the species) is at stake. Breeding is a transport mechanism: handing the precious cargo of genetics down generations of "organic containers".
But this is a reductionist view, which both ignores epistemological and emotional realities - and is tautological, thereby explaining something in terms of itself. Calling something by a different name or describing the mechanisms involved in minute detail does not an explanation make.
First hypothesis: we bring children to the world in order to "circumvent" death. We attain immortality (genetically and psychologically - though in both cases it is imaginary) by propagating our genetic material through the medium of our offspring.
This is a highly dubious claim. Any analysis, however shallow, will reveal its weaknesses. Our genetic material gets diluted beyond reconstruction with time. It constitutes 50% of the first generation, 25% of the second and so on. If this were the paramount concern - incest should have been the norm, being a behaviour better able to preserve a specific set of genes (especially today, when genetic screening can effectively guard against the birth of defective babies). Moreover, progeny is a dubious way of perpetuating one's self. No one remembers one's great great grandfathers. One's memory is better preserved by intellectual feats or architectural monuments. The latter are much better conduits than children and grandchildren.