Evidence of organized but not disorganized attachment in wild Western chimpanzee offspring (Pan troglodytes verus)

Human attachment theory outlines three organized types: secure, insecure avoidant and insecure resistant, all considered adaptive responses to maternal care for offspring survival. In contrast, disorganized attachment is hypothesized to be maladaptive and therefore uncommon in wild mammals, though this remains untested. We assessed attachment types in 50 wild chimpanzees (ages 0–10 years) in Taï National Park, Côte d’Ivoire. Using 3,795 h of mother and offspring focal observations, we found no behaviours indicative of disorganized attachment. To explore organized attachment, we analysed a subset of 18 immature chimpanzees and their behavioural responses to 309 natural threatening events. Their responses showed organized attachment patterns: some sought maternal closeness (secure-like), while others displayed independence (insecure avoidant-like). Our study supports the hypothesis that organized attachment types are adaptive and have a long evolutionary history.