Attachment,Intelligence, and Language: A Meta-analysis†

In attachment theory, several hypotheses about the association between attachment and cognitive development have been generated. In a series of meta-analyses on 32 studies, we tested whether the quality of attachment is related to intelligence (DQ or IQ) and to language competence. Attachment showed a weak association with DQ and IQ measures (combined r = .09; N = 1026). The combined effect size for the relation between attachment and language competence was r = .28 (N = 303). We conclude, first, that differences in intelligence do not play a major role in shaping attachment relationships. Differences in quality of attachment are not confounded in any significant way with differences in intelligence. Second, secure children appeared to be more competent in the language domain than insecure children. Language development appears to be stimulated in the context of a secure attachment relationship because secure parents may be better ‘teachers’ and secure children may be better motivated ‘students’.