What was the procedure that Van IJzendoorn and Kroonenberg used?
They found 32 studies where the Strange Situation had been used to investigate the attachment type of babies. These were conducted in 8 different countries - 15 were in the US. Overall 1990 babies were studied.
What were the findings of IJzendoorn and Kroonenberg's research?
There was a wide variation between the proportions of attachment types:
Secure attachment was the most common across all countries
It ranged from 75% in Great Britain to 50% in China
Insecure-avoidance was lowest in all countries except for Israel and Japan
