Frank van der Horst earned his Ph.D. at Leiden University in 2009 and has published widely on (the history of) attachment theory. His current research at Erasmus University Rotterdam aims at describing the history of ideas in the behavioural sciences, such as the ideas and work of John Bowlby, René Spitz, William Goldfarb, and Harry Harlow. His aim is also to further unravel the roots of attachment theory in, for example, the work of James Robertson and that of developmental psychologist Mary Ainsworth. These studies are necessary to complete our picture of the historical embeddedness of theoretical innovations in (developmental) psychology. Van der Horst is the author of John Bowlby – From Psychoanalysis to Ethology. Unraveling the Roots of Attachment Theory (2011), John Bowlby. Dalla psicoanalisi all'etologia (2012), Opgroeien in het hedendaagse gezin (2016/2020, with others), Hechten. Menselijke emoties, relaties en ontwikkeling (2024, editor, with others), Opgroeien en opvoeden. Handboek Pedagogiek (expected 2025, editor, with others), and John Bowlby - A Contemporary Introduction (expected 2025).

Van der Horst also obtained a Psy.D. while working in forensic psychiatry and holds Dutch clinical registrations as Psychotherapist (99916765216), GZ-psychologist (79916765225), Orthopedagoog-Generalist (09916765231) and supervisor NVO (9819) and NIP (242965). Currently, he is involved in clinical supervision of graduates and postgraduates and clinical assessment and treatment in forensic psychiatry.

Specialties:
- Clinical applications of attachment theory
- History of ideas in psychology and education
- Forensic psychiatry
- Personality disorders
- Domestic violence & child abuse
- Psychotherapy