Psychoanalytical theory proposes that the syndrome evolves from the man’s envy of the woman’s procreative ability. The theory also proposes that for the male partner, the pregnancy acts as a catalyst for the emergence of ambivalence and the resurgence of oedipal conflicts. The event may cause regression — the man’s retreat to childhood feelings and conflicts triggered by his partner’s pregnancy, such as rejection, exclusion, ambivalence, and anxiety — with a sense of passivity and dependency that is intensified by the developing foetus and which conflicts with the man’s need for autonomy.
A second psychoanalytical theory proposes that expectant fathers may sometimes view the unborn child as a rival for maternal attention. Some have explained this as the expectant father’s interpretation of the unborn baby as a rival from whom attention is diverted. But this is expressed through a more socially acceptable outlet such as the syndrome. This interpretation would suggest that the syndrome has a protective function for the man because it enables him to identify with his pregnant partner and strengthens his protective instincts towards her and the baby.