The growth point is a theoretical unit of language and thought proposed as the initiating cognitive unit in the production of speech. Growth points are inferred from speech-gesture synchrony and co-expressivity, and incorporate elements from the context of speaking by virtue of what Vygotsky (1987) called ‘psychological predicates.’ The psychological predicate in any given case can be known only in relation to its local context, from which it is the point of differentiation. Thus growth points, as psychological predicates, incorporate context as an inherent property. The first part of the paper consists of a detailed case study of the growth point of a recorded English utterance. The aim is to demonstrate how this growth point was inferred and how it, and no other, and the full sentence it was unpacked into, could have been products of contextual differentiation. The growth point ‘predicts’ a context, which must be observed in order to validate the growth point in each given case. An essential tool of analysis is the concept of a catchment—a thematic unit in gesture revealed through partial form and space recurrences. In our case study, three catchments are involved. The second part of the paper consists of a comparison of the growth point to Kita's information packaging hypothesis. One difference is that the growth point defines psychological units whereas the information packaging hypothesis, despite its name, does not. This part of the paper also presents an analysis of gestural foreshadowing as seen in a cross-linguistic example (Turkish). Foreshadowing at first glance seems problematic for the growth point, because synchrony appears to break down, but in fact it leads to new insights into mechanisms of growth point composition. The paper concludes with the statement that language is inseparable from imagery—a concept not deducible from the tradition of text-based linguistic analyses. Imagery requires finding new theoretical concepts about language in non-traditional domains.