- Key study 1: Van Ijzendoorn and Kroonenberg - Meta-analysis:
- Procedure - The researchers looked at the proportions if secure, insecure-avoidant and insecure-resistant attachments across a range of countries. They also looked at the differences within the same countries to get an idea of variations within a culture.
- They found 32 studies of attachment where the Strange Situation had been used. These were conducted in 8 countries. 15 in the USA. Overall the studies yielded results for 1,990 children. The data was meta-analysed, results being combined and weighted for sample size.
- Findings - Secure attachment was the most common classification in all countries, but ranged from 50% in China to 75% in Britain. In individualist cultures rates of insecure-resistant attachment were similar to Ainsworth's origional sample (all under 14%) but this wasn't true for the collectivist samples from China, Japan and Isreal where rates were abover 25% (and where rates of insecure-avoidant attachment were reduced). This suggests that there were cultural differences in the distribution of insecure attachment.
- Variations between results of studies within the same country were actually 150% greater than those between countries. In the USA, one study found 46% securely attached compared to one sample as high as 90%.
- Key Study 2: Simonelli et al - An Italian key study:
- Procedure - These researchers assessed 76 12-month olds using the Strange Situation to see whether the proportion of attachment types still matched previous studies in Italy. Mothers were reasonably varied in terms of their education levels (57% Uni degree, 40% high school, 2% didn't finish high school…