In the course of systematic longitudinal developmental studies and clinical assessments, I have paid special attention to the observable behavioral regulation of affect states for the better understanding of ego development in infants (i.e., children under 3 years of age). Some of the methods and conceptualizations developed in this process, as well as some of their clinical applications, are the subject of this paper.

Unfortunately, the terms “affect” and “emotion” are often used interchangeably, with a confusing multitude of definitions applied to both. Basch (1976) suggested that the term emotion should be used to refer to a degree of psychological development where the level of self-object differentiation has started to allow at least some reflection on one's own subjective experiences. It seems to be a useful and important distinction that the newborn infant cannot yet