The arrival of a younger child in the family is usually perceived and described as a joyful event. Yet it simultaneously initiates complex emotional processes, particularly for the firstborn. For example, Donald Winnicott (1991) emphasised that the older child may experience this as one of the most traumatic events of early childhood.

During the mother’s pregnancy, the firstborn often experiences intense anxiety, which frequently remains buried within the unconscious, though it may also be partially conscious. Moreover, the older child may regress: they might begin to suck their thumb again, lose toilet training skills (enuresis or encopresis may appear), or re-experience separation anxiety, and so on.

The child may start to fantasise about being excluded or no longer needed, and feel a threat to their identity — after all, they will soon cease to be the only child in the family, lose their “right to exclusivity”, and be forced to share parental attention with the younger sibling.

Surprisingly, even before the younger sibling is born, many firstborns begin to intuitively sense and emotionally respond to the approaching changes. According to several analysts, the older child may affectively register and feel the coming presence of the younger sibling long before they can cognitively grasp or verbalise what is happening.

This foreboding activates unconscious fantasies, drives them to seek confirmation, and triggers behavioural and attachment shifts, as well as emotional instability. The older child may not fully understand the biological reality of the mother’s pregnancy but may unconsciously sense her reduced emotional availability, reacting with psychic tension and inner restlessness.

From a Kleinian perspective, the older sibling may begin to fantasise about the foetus as a “bad object” that seeks to take away the mother’s love and sever the bond that once guaranteed the child’s sense of safety and omnipotence. Such a fantasy can activate the most primitive forms of anxiety and defensive mechanisms.

News of the upcoming birth may also significantly amplify the older child’s Oedipal anxieties — feelings of exclusion, worthlessness, injustice, disappointment, anger, envy, and jealousy. Although the Oedipal triangle originally involves the parents, the arrival of a new baby modifies this dynamic by introducing a horizontal axis of rivalry, as Juliet Mitchell (2003) highlighted.

Envy and so-called sibling jealousy toward the unborn or already born younger child may manifest in the older child’s unconscious fantasies of eliminating or harming the baby. Such aggression can coexist with genuine interest and joy, producing an emotional ambivalence that the older child cannot process alone.

Many analysts have heard from patients — themselves older siblings — how they behaved destructively toward the newborn: trying to “get rid of” the baby, “evicting” it to the hallway, attempting to throw it away, push it off a balcony, or feed it “grown-up” food, and so on.

When adequate containment by adults is lacking, the older child’s unprocessed emotional experiences may persist in the psyche as unsymbolised, raw sensations. These can develop into chaotic fantasies of replacement, cannibalistic imagery, or fantasies of omnipotently rescuing the younger child. These fantasies reflect an attempt to process and re-symbolise the shifting emotional reality.

It is crucial to remember that parental responses play a key role here: whether the child’s emotions are named, acknowledged, or rejected will determine whether they become integrated into the psychic structure or remain fragmented, persecutory states that may linger for years.

When the older child is still awaiting or has already encountered the birth of a sibling, questions about their own identity and belonging may arise. According to Juliet Mitchell, sibling relations introduce the element of comparison into the older child’s psychic development. The child begins to question their uniqueness and their place in the family structure.

This may destabilise the developing ego and cause a narcissistic wound. However, this same period can also stimulate growth. Some children begin to identify with the parental function, imitating caring behaviours and forming their first ego ideals. In this way, the symbolic role of being “the older one” starts to integrate into the developing ego.

On the other hand, the older child’s emotional experience is also shaped by cultural narratives and parental interaction strategies. In cultures where the firstborn retains a special status regardless of the arrival of younger siblings, the narcissistic wound may be less pronounced.

Parental strategies such as involving the older child in preparing for the new baby, affirming the child’s significance, and containing their emotions can reduce the traumatic potential of the situation. But if parents themselves hold ambivalence about the new child, the older child may act out this split, which only exacerbates their internal conflict.

Thus, the emotional experience of the older child during the mother’s pregnancy with the younger sibling represents a complex interplay of intrapsychic processes and external factors. This transitional period is far from simple; it is an important developmental stage that may shape the nature of the child’s future relationships for many years to come.

Winnicott, D. (1991). The Child, the Family and the Outside World.
Mitchell, J. (2003). Siblings: Sex and Violence.