People / Cognitive, behavioural and contextual
Steven C. Hayes
Helped develop an approach that describes psychological flexibility through six interconnected processes.
At a glance
Born 1948. American. Clinical Psychologist.
Active 1982 to present. Landmark year 1999. Clinical era: 1990 to 2009, contextual, attachment and trauma.
Lineage: Cognitive, behavioural and contextual. Roles: Modality founder or co-founder; Clinical theorist; Process and outcome researcher.
Associated modalities: Acceptance and Commitment Therapy (ACT); Process-Based Therapy (PBT).
Clinical psychologist and co-developer of acceptance and commitment therapy and relational frame theory.
Review status: Educational draft, subject review pending. Source status: source checks not documented for this draft. Dates, sources and clinical statements require independent verification and specialist review.
Clinical overview
Steven C. Hayes is an American clinical psychologist educated at West Virginia University and a professor emeritus at the University of Nevada, Reno. His work includes contextual behavioural science and the development of acceptance and commitment therapy (ACT).
With Kirk Strosahl and Kelly Wilson, Hayes developed ACT, an approach informed by functional contextualism and relational frame theory (RFT), a behavioural account of language and cognition. ACT emphasises a person’s relationship with thoughts and feelings and action guided by chosen values.
Historical and clinical context
Acceptance and Commitment Therapy: An Experiential Approach to Behavior Change appeared in 1999. Psychological flexibility is central to the ACT model and has been studied as a possible process of change. Research into these processes continues; findings do not establish a single mechanism for every person.
In later decades, Hayes collaborated with Stefan Hofmann to formulate Process-Based Therapy (PBT), moving beyond disorder-specific diagnostic manuals toward idiographic networks of biopsychosocial change processes.
Core therapeutic contributions
Relational Frame Theory (RFT) and Functional Contextualism. RFT proposes an account of language and cognition based on learned relations between stimuli. Hayes and colleagues connect this account to their model of psychological flexibility.
Experiential Avoidance and Cognitive Fusion. The ACT model identifies experiential avoidance and cognitive fusion as processes that can contribute to behavioural rigidity; these are proposed processes rather than universal causes of distress.
The Six-Process Psychological Flexibility Hexaflex. Organised clinical work around six interconnected processes: Acceptance, Cognitive Defusion, Present-Moment Awareness, Self-as-Context (the observing self), Values Clarification, and Committed Action.
Creative Hopelessness as Clinical Opening. Guided clients to examine gently the unworkability of their lifelong emotional control agenda before introducing willingness as an alternative stance.
In the consulting room
Therapeutic stance. Egalitarian, experiential, metaphor-rich fellow traveller ('two mountains' metaphor) who sits inside the same human traps of language alongside the client and models willingness, defusion, and values-based vulnerability.
Signature practices. Exploring 'creative hopelessness' by mapping what the client has tried to eliminate pain, how it has worked in the short and long term, and what it has cost in vitality; Using experiential cognitive defusion exercises (such as 'I am having the thought that...', singing a thought, or placing thoughts on leaves on a stream) to loosen literal believability; Using physicalised metaphors (Passengers on the Bus, Tug-of-War with a Monster, Chinese Finger Trap) to contrast struggle with willingness; Distinguishing chosen values (ongoing directions of action) from concrete goals and linking small committed actions to what matters most
Common misreadings. Using cognitive defusion or acceptance exercises as covert emotional-control tricks to make anxiety disappear; Rattling off stock ACT metaphors mechanically without functional assessment of the client's in-session avoidance or fusion moves
Landmark clinical works
1999, Acceptance and Commitment Therapy: An Experiential Approach to Behavior Change (with Kirk D. Strosahl and Kelly G. Wilson; 2nd ed. 2012) (book). Landmark clinical text introducing the ACT model, functional contextualism, and the psychological flexibility framework.
2001, Relational Frame Theory: A Post-Skinnerian Account of Human Language and Cognition (with Dermot Barnes-Holmes and Bryan Roche) (book). Basic behavioural science treatise explaining arbitrarily applicable relational responding as the foundation of human symbolic thought.
2005, Get Out of Your Mind and Into Your Life (with Spencer Smith) (book). Translated ACT principles of defusion, willingness, and values into an accessible self-directed workbook.
2019, A Liberated Mind: How to Pivot Toward What Matters (book). Synthesised three decades of research on psychological flexibility and recounted the personal and scientific origins of ACT.
Clinical critiques and limitations
Traditional cognitive therapists (including Aaron Beck and Stefan Hofmann in early debates) argued that cognitive defusion and acceptance overlap substantially with decentring and behavioural experiments in classic CBT.
Relational Frame Theory's technical terminology can feel formidable to practitioners, leading many clinicians to adopt ACT metaphors without engaging its underlying functional-analytic theory.
A 2022 systematic review of acceptance- and mindfulness-based therapies for anxiety and depression found evidence concerning proposed mediators, but limitations in the studies restricted conclusions about causal effects and whether mediators were specific to these therapies. The review covered a broader group of approaches than ACT alone.
Clinical genealogy
Influences and mentors: B. F. Skinner; John Cone; David H. Barlow.
Collaborators: Kirk D. Strosahl; Kelly G. Wilson; Dermot Barnes-Holmes; Robyn D. Walser; Stefan G. Hofmann.
Students and successors: Kelly G. Wilson; Robyn D. Walser; Louise McHugh; Russ Harris.
Sources and inspection notes
Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (1999). Acceptance and Commitment Therapy: An Experiential Approach to Behavior Change. Guilford Press.
Supports: A dated check of its relevance to this profile is not recorded for this draft
Hayes, S. C., Barnes-Holmes, D., & Roche, B. (Eds.). (2001). Relational Frame Theory: A Post-Skinnerian Account of Human Language and Cognition. Kluwer Academic/Plenum.
Supports: A dated check of its relevance to this profile is not recorded for this draft
Supports: A dated check of its relevance to this profile is not recorded for this draft
Supports: A dated check of its relevance to this profile is not recorded for this draft
University of Nevada, Reno. Steven C. Hayes: Department of Psychology profile.
Supports: A dated check of its relevance to this profile is not recorded for this draft