ABSTRACT
Family therapy has benefited greatly from the advances in evidence-based practice and practice-based evidence; yet, the foundational theory of family therapy – family systems theory – has been largely reliant on proposals and hypotheses put forward more than 50 years ago. This chapter defines family systems theory and provides two hypotheses – that the family is an autonomous system and that the family is an adaptable system. These two hypotheses can tie together diverse proposals from across family systems research and provide clear, testable hypotheses that can be evaluated by evidence.
