Attachment - Key studies

Harlow 1959 - Monkeys

Harlow separated 16 rhesus monkeys from their biological mothers at birth and raised them in a lab with 2 surrogate mothers (1 wire who provided food, and 1 cloth who provided comfort). Monkeys spent 18hrs with cloth, and 1hr with wire, only when needed food. When confronted with a fear stimulus (diabolical machine), they sought protection and comfort from cloth mother. Grew up in maternal deprivation and suffered consequences e.g. aggression, abnormal social behaviours and became bad mothers themselves.

Lorenz 1935 - Geese

Lorenz separated a clutch of goose eggs and randomly allocated half to stay with the mother and half to be raised in an incubator. For the eggs in the experimenter condition, Lorenz was the first moving object they saw. When the goslings were older, he placed all the goslings from both conditions in a box and set them loose. Each gosling ran to whoever they had imprinted on. Also introduces the idea of a critical period.

Bowlby 1944 - Consequences of maternal deprivation

44 juvenile thieves and 44 adolescents who had committed no crimes. Each P and their parents were given tests to assess IQ and interviewed about their childhood. Over 50% of the thieves experienced a period of more than 6 months separation from their mothers during their first 5 years, vs only 2 from control group. 32% of the thieves were affectionless psychopaths. Of these affectionless psychopaths, 86% had experienced maternal separation. Bowlby also found long separation correlated with low IQ.

Rutter 1998 - ERA

Longitudinal study called English and Romanian Adoptee study (ERA). Tracked the development of approximately 150 Romanian orphans who were adopted by English families. Those adopted before 6 months had an average IQ of 102 (UK average is 100). Those who were adopted after 6 months displayed a disinhibited attachment style (attention seeking no stranger anxiety and clingy behaviour). Those adopted after 2 years had a mean IQ of 77 (75 is the threshold for mentally disabled).

Ainsworth 1970 - Strange situation

A controlled lab observation covertly observing children’s responses to various situations. Ainsworth used a behavioural checklist with time sampling every 3 minutes to assess attachment styles from: proximity seeking, exploration, stranger anxiety, separation anxiety and response to reunion. She concluded 3 attachment types from this observation - secure, insecure-avoidant and insecure-resistant.

Van Ijzendoorn and Kroonenberg 1988 - Cultural variations

Conducted a meta-analysis of 32 studies (over 2000 children from across 8 different countries) that had used the Strange Situation to investigate attachment types. Secure was the most common attachment type across all countries studied. Insecure-avoidant was most common in Germany (35%) and insecure-resistant was most common in Israel (29%).

Hazan and Shaver 1987 - Love quiz

620 participants answered a questionnaire in a newspaper. The questionnaire assessed childhood attachment type and P’s attitudes towards love. They found Ps who had a secure attachment were more likely to have a secure/balanced/positive/trusting/long-lasting romantic relationships. Insecure-resistant viewed love as a compulsory commitment and were constantly worried about abandonment. Insecure-avoidant feared closeness and didn’t think they needed love to be happy. Supports idea of an internal working model.

Main et al. 1985 - Adult Attachment Interview

The Adult Attachment Interview assesses how early attachment experiences shape adult personalities. Findings reveal three patterns: 1) Secure adults have a positive view of self and others, valuing relationships and discussing childhood experiences positively; 2) Dismissive-avoidant adults have a positive self-image but negative views of others, avoiding intimacy; 3) Preoccupied adults possess a negative self-image and seek validation from others, relying heavily on relationships.