Experimental Design: Harlow compared the reactions of infant monkeys to two surrogate mothers: one made of bare wire that provided milk, and one covered in soft cloth that provided no food.
The Primacy of Comfort: The infants spent significantly more time with the cloth mother, only visiting the wire mother to feed, demonstrating that contact comfort is more important than food for attachment.
Response to Stress: When frightened, the monkeys consistently sought refuge with the cloth mother, using her as a 'secure base' to regain confidence before exploring.
Maternal Deprivation: Monkeys raised in total isolation or with only wire mothers showed severe social abnormalities, including extreme aggression and an inability to interact with peers or care for their own offspring.
| Feature | Lorenz (Imprinting) | Harlow (Contact Comfort) |
|---|---|---|
| Species | Birds (e.g., Geese) | Mammals (Rhesus Monkeys) |
| Primary Driver | Visual/Movement (Innate following) | Tactile (Physical softness) |
| Critical Period | Very short (hours) | Longer (months) |
| Focus | Survival/Following behavior | Emotional security/Social development |
| Adult Impact | Sexual mate selection | Social and parenting competence |
Extrapolation Issues: Always mention the difficulty of applying findings from birds or monkeys directly to humans, as human attachment is significantly more complex and cognitively driven.
Ethical Evaluation: Be prepared to discuss the ethical costs of Harlow's work (psychological harm to monkeys) versus the benefit of understanding the necessity of emotional care in orphanages.
Nature vs. Nurture: Use these studies to argue for the 'nature' side of the debate, as they suggest attachment is an evolved, biological drive rather than a purely learned behavior.
Terminology Precision: Do not confuse 'imprinting' (Lorenz) with 'contact comfort' (Harlow); though both relate to attachment, they describe different biological mechanisms.
The Food Fallacy: A common mistake is assuming Harlow proved food is irrelevant; rather, he proved food is not the primary basis for the emotional bond of attachment.
Imprinting Permanence: While Lorenz argued imprinting is irreversible, later researchers found that imprinting effects can sometimes be modified through later social experiences, though it remains difficult.
Human Imprinting: Students often incorrectly state that humans 'imprint'; humans do not have a rigid imprinting mechanism like birds, but rather a 'sensitive period' for forming attachments.
