I believe a major factor in the well-being of an infant and his secure attachment may be associated with culture. Kids growing up in different cultures will obviously have been raised differently. Depending on the culture, parents of a child will treat the child strictly, harshly, or gently and lovingly. Culture plays a major role because there are a set of beliefs and standards that each family sets and the family expects each family member to abide by them. If a culture makes parents treat their child with barely any love and care, then that child will be more prone to insecure attachment and a not-so-well being in the future.
I understand the point being made, but i do think that within cultures there will bee different parenting styles that turn out different kids with different attachment styles. There is deffinitely a correlation with culture but I don't think it is as absolute as you make it sound.
I agree with you based on my personal experience. I grew up outside the United States and my parents reared me with a totally different cultural style than the ones I have seen here. I was not given the caring that I really wanted. When I was a kid, I was not securely attached because I didn't really care whether my mother was present or not (stories omitted). And I do believe if I lived under a different culture, my understanding of/reaction to parental love would be quite different.