Why do we have a chapter on temperament in a volume primarily devoted to the concepts of attachment and affiliation? Years ago, such a chapter would have been unthinkable because attachment and temperament appeared to refer to different phenomena. Classic theories of mother-infant relations such as those of Spitz (1965) and Bowlby (1951) leaned in the direction of a “tabula rasa” model of the human infant by proposing that emotional and drive-regulating experiences provided by the mother were crucial for the formation and maintenance of ego functions. The individual differences these theorists were interested in were those resulting from successes and failures of maternal interaction, although on occasion they did invoke genetic and constitutional factors to account for unusual tolerances or susceptibilities to the ill effects of maternal separation. Individual differences in temperament, then, were …