Background:  Despite the evidence on anomalous attachment patterns, there has been a tendency to interpret most of these as reflecting differences in security/insecurity. Methods:  Empirical research findings are reviewed in relation to attachment/insecurity as evident in both infancy and later childhood, disorganised attachment, inhibited attachment disorder, and disinhibited attachment disorder. Findings:  Substantial differences are found in the correlates and meaning of these different features, as well as in the patterns associated with conditions such as autism, psychopathy, and Williams syndrome. Conclusions:  It is seriously misleading to view all of these patterns through the lens of security/insecurity. This heterogeneity in social relationship features necessarily has implications for the assessment measures for social relationships that need to be used.