Little Me Grows the Way My World Shows - Older babies or Toddlers Reacting Negatively to a New Family Member "occupying their rightful place," - UKJNews

The video from the X post is a lighthearted montage of various toddlers encountering newborn siblings in hospital settings, often with dramatic facial expressions, crying, pointing, or tantrums.

Overlaid captions humorously anthropomorphize their reactions as jealous outbursts like "Why two babies?!", "No!! Extra!!", "But... I was first!", or "He's not cute. I am cuter." 

While some commenters speculate it's AI-generated, it captures a common real-world phenomenon: older babies or toddlers reacting negatively to a new family member "occupying their rightful place," as appear in the video. This ties into about tabula rasa—the idea of the mind as a blank slate at birth, popularized by John Locke but echoing Aristotle's "unwritten tablet" in De Anima, Ibn Sina's (Avicenna's) blank mirror or slate, and the Stoics' emphasis on experience shaping knowledge without innate ideas. Yet, as we note, infants develop a sense of belonging and proprietary anger remarkably fast, suggesting that while the slate may start blank, evolutionary instincts or rapid sensory learning quickly inscribe possessive behaviours. 

Below, I'll explain this reaction through the lenses of: psychological, social constructs, the five senses, the mind, and societal constructs, drawing on how these manifest in observable behaviours.

Psychological Perspective

From a developmental psychology standpoint, this reaction is a classic example of sibling rivalry, where the older child perceives the newborn as a threat to their established bond with parents and access to resources like attention, affection, and care. It's normal and peaks in toddlers (ages 1-3), who may regress (e.g., bedwetting, thumb-sucking), act aggressively toward the baby, or become clingy and hostile toward parents. Evolutionarily, this stems from an instinctive fear that the new sibling could divert survival essentials—rooted in ancestral contexts where parental investment was finite, making jealousy a adaptive response to competition. Factors like the child's temperament play a key role: those with "difficult" temperaments (e.g., high irritability, low adaptability) show stronger jealousy, mediated by poor emotion regulation skills. Age gaps matter too—larger gaps reduce jealousy as the older child is more secure, while closer spacing intensifies it. Despite tabula rasa implying a purely experiential basis, this quick onset (sometimes within days) hints at innate emotional wiring, blended with learned associations from prior undivided attention.

Here are a few visual examples of similar toddler reactions to new siblings:

From the Five Senses

Babies and toddlers process the world primarily through sensory input, which rapidly builds their sense of "mine" versus "intruder." Even with a blank slate start, repeated sensory experiences etch territorial responses:

Sight: The visual cue of seeing parents cradling or feeding the newborn triggers recognition of displacement. Toddlers, with developing object permanence, notice the baby occupying spaces (like laps or bassinets) that were once theirs, leading to stares, frowns, or attempts to push the sibling away.

Hearing: The newborn's cries demand immediate parental response, disrupting the toddler's auditory environment. This can evoke frustration as the toddler associates the sounds with lost playtime or comfort, amplifying feelings of exclusion.

Touch: Reduced physical contact—fewer hugs, carries, or cuddles—creates a tactile void. Toddlers may seek to reclaim this by clinging or even roughly handling the baby, interpreting the lack as rejection.

Smell: New scents from baby products, milk, or the infant's natural odor signal change. Olfactory memory links familiar parental smells to security; the intrusion of unfamiliar ones can heighten unease.

Taste: Less direct, but shifts in routines (e.g., hurried meals or shared breastfeeding times) might alter feeding experiences, associating the sibling's presence with dissatisfaction or scarcity.

These sensory inputs accumulate swiftly, turning the "unwritten tablet" into one inscribed with proprietary claims.

The Mind

Cognitively and emotionally, the toddler's developing mind struggles with abstraction, making the newborn's arrival a concrete threat. Per Piaget's preoperational stage, toddlers are egocentric, viewing the world from their perspective alone—they can't fully grasp sharing or the baby's needs, so they interpret parental divided attention as personal loss. 

Emotionally, the limbic system processes this as anger or sadness, drawing on early memories of being the sole focus. While tabula rasa posits no innate knowledge, the mind's rapid plasticity allows quick learning: within weeks, associations form between the sibling and negative emotions, manifesting as protests or withdrawal. This isn't purely blank—innate drives like attachment (Bowlby's theory) prime the mind for bonding, but also for defending it against perceived rivals.

Social Construct

Socially, the family unit is a constructed micro-society where roles are assigned and learned through interaction. The "rightful place" we all know is a social artifact: the older child has been socialized as the "baby" of the family, with undivided privileges. The newborn disrupts this hierarchy, forcing a shift to "big sibling" status, which society frames as positive (e.g., helper role) but feels like demotion to the child. Interactions like parental encouragement ("Be gentle with your brother") reinforce this construct, but if mishandled, amplify resentment. In group settings (e.g., playdates), toddlers observe peer dynamics, learning belonging through comparison, which accelerates possessive behaviours.

Societal Constructs as They Appear to Us

Societies construct family norms that shape how these reactions "appear" in our perceptions—often romanticized or pathologized. In individualistic cultures (e.g., Western), emphasis on personal autonomy heightens the toddler's sense of entitlement, making jealousy seem more pronounced and "natural." Collectivist societies (e.g., many Asian or African) stress communal roles, where older siblings are expected to nurture, potentially muting overt anger but internalizing it as duty. Birth order myths, like primogeniture (favouring firstborns in inheritance), culturally validate the "rightful place," making displacement feel like a societal betrayal. Phenomenologically, as these appear to us, we interpret toddler tantrums through our lenses—humorously in viral videos, or clinically in psychology—revealing more about societal values (e.g., nuclear family ideals) than innate traits. Yet, cross-culturally, the core reaction persists, blending blank-slate learning with universal human territoriality.