Constructions are long-term pairings in memory of form and meaning. How are they created and learned, how do they change, and how do they combine into new utterances (constructs, communicative performances) in working memory? Drawing on evidence from word-formation (blending, Noun-Noun-compounds) over idioms and argument structure constructions to multimodal communication, we argue that computational metaphors such as 'unification' or 'constraint-satisfaction' do not constitute a cognitively adequate explanation. Instead, we put forward the idea that construction combination is performed by Conceptual Blending - a domain-general process of higher cognition that has been used to explain complex human behavior such as, inter alia, scientific discovery, reasoning, art, music, dance, math, social cognition, and religion. This title is also available as Open Access on Cambridge Core.