Who We Are
Jonathan’s passion lies in developing people, especially in management and leadership roles. He is a counselling psychologist and his teaching, research and consulting interests include self-assessment and peer feedback in leadership and management development.
He is chairman and chief consultant of Thornhill Associates. One of his contributions has been to develop the standard Thornhill 360° questionnaires, drawing on his expertise in psychological assessment and experience in management education.
After qualifying as a counselling psychologist, and working with community and church-based organisations for several years, he spent ten years with the National Institute for Personnel Research in Johannesburg, finally as Head of Assessment and Counselling. His next fifteen years were spent as a faculty member at the Graduate School of Business Administration of the University of the Witwatersrand (Wits Business School), where he founded the Management Development Unit and later became director of academic programmes.
In 2004 he joined the Gordon Institute of Business Science (GIBS) of the University of Pretoria as senior lecturer, and in 2011 was appointed Director, a position he held until December 2013. He still teaches part time at GIBS in the areas of leadership and personal development, including the MBA core course Human Behaviour and Performance in SA and an MBA elective called The Moral Leader.
He left GIBS to devote more time to Thornhill and to the African Management Initiative (AMI –www.africanmanagers.org ), which he helped found and currently chairs. AMI is a social enterprise focused on developing scalable approaches to supporting African managers in excellent performance.
Jonathan is the past chairman of the Association of African Business Schools and currently serves as chairman of Tomorrow Trust and BizSchool.
He and Sally have two sons, and (so far) two granddaughters and two grandsons.
Daphne joined Thornhill Associates in March 2006. She was admin manager until her appointment as CEO in July 2012. Daphne is a registered counselling psychologist as well as a qualified coach, and she maintains a private practice.
Prior to joining Thornhill, Daphne was self-employed for seven years. During this time her main contracts included conducting research for Africa’s leading publishing group and acting as project manager for P3 Management Consultants. She also spent four years with Hay Management Consultants SA (part of the HayGroup) as senior consulting assistant and support team leader, and Daphne co-ordinated the marketing activities for Hay SA in Africa.
She started her career in 1987 in the IT industry. Daphne was the admin consultant for SilverLine Resources (an IT Contracting, Recruitment and Consulting company) for seven years, before moving to SQL Integrators (now Sybase SA) to support the sales team.
Daphne holds an MA Counselling Psychology (cum laude) from the University of Johannesburg, and completed her internship at the Centre for Psychological Services and Career Development (PsyCaD). She has a BA Hons (Psych) from the University of Johannesburg and a Bachelor of Arts (Psychology and Communication) degree from UNISA. Daphne also holds Myers-Briggs Type Indicator® (MBTI®) International Accreditation, as well as a Brain Based Coaching Certificate from Results Coaching Systems and NeuroLeadership Group.
She is passionate about people development and helping others become all that they can be in every area of their lives. Daphne believes that people can change and volunteers as a co-facilitator for the Alpha course in Leeuwkop Maximum Prison. She thoroughly enjoys travelling and experiencing different cultures, as well as rollercoasters, mountain biking, hiking and reading.
Daphne is married and blessed with a son and a daughter.
Martin Cook’s passion is to use creative problem solving and technology to improve people’s lives.
He has a PhD in applied nuclear physics, pioneering a technique to locate diamonds in kimberlite streams using a combination of particle accelerator physics and nuclear medicine. His Masters degree is in string theory, a branch of physics attempting to understand the universe at a fundamental level. He is currently pursuing the commercialisation of his PhD.
Martin worked part time for Thornhill between 2004 and 2014. During that time, he also held positions as a system administrator of a research cluster computer at Wits University, a database developer at a group of HIV/TB clinics and a programme manager at the University of Johannesburg, setting up a new Masters level course in nuclear energy.
After submitting his PhD thesis at the beginning of 2014, he headed up the Thornhill development team until mid 2015. Since then, he has stepped out of day-to-day Thornhill operations, but remains active as a director on the board, and provides occasional input into the development team.
Martin’s biggest joy in life are his daughter (who is, without doubt, the most gorgeous girl on the planet) and his son (who is, without doubt, gearing up to take over the world).
Consultants, Coaches and Researchers
Verity has over 20 years’ experience in both corporate and small businesses in South Africa, where she has been involved in many different aspects of general management. For the last 10+ years she has been specialising in professional and personal leadership development and enjoys several roles within this area. Verity started working with Thornhill Associates in 2008 and acts as a consultant and coach. In addition, she is a Professional Associate at the Gordon Institute of Business Science (GIBS) where she is involved in personal development and action learning coaching, programme integration, mentoring, case study writing, lecturing and supervision of MBA research. Verity is also a leadership development coach in her private capacity.
Verity’s qualifications include an MBA from GIBS, a Post Graduate Diploma in Management (Business Administration) from Wits Business School, and BA degree (English and French Studies) from the University of Kwazulu-Natal, Pietermaritzburg campus. Verity is an Accredited Certified Coach (ACC) with the International Coach Federation (ICF) and she has completed the following coaching courses: Professional Business Coaching Programme (GIBS), Advanced and Fundamentals of Organisation and Relationship Systems Coaching (ORSC) (CRR Global), Executive Personal and Leadership Coaching (The People Business). In addition, she has attended further learning courses, namely: Leader as Mentor (GIBS), Depth Facilitation (Depth Leadership Trust), Competitive advantage through management innovation (GIBS), and HIV/AIDS Pre-& Post-test Counselling Skills (Family Life Centre). Verity has published several teaching case studies through the Richard Ivey School of Business, University of Western Ontario.
Verity is an outdoor enthusiast; she loves bird watching, camping in remote places, mountain biking, trail and road running (she has completed the Comrades ultra marathon; great fun, but never again!). Verity volunteers as a reader for Tape Aids for the Blind.
Verity is married with a teenage daughter and two wild Boxer dogs.
Cedric de Beer joined Thornhill Associates in March 2018 as a consultant and coach. Cedric has a life time of experience of establishing organisations, building and leading executive teams and supporting colleagues launch their careers.
From co-founding a rural development agency in the 1970’s, establishing and co-directing a policy research unit at Wits Medical School in the 1980’s, and being the first CEO of a Housing Finance company for fourteen years from 1995, Cedric has brought persistence, imagination and high standards of ethical leadership to the creation of social enterprises in various sectors. From 2009 he was Director of African Operations for the Soros Economic Development Fund – a New York based social impact investment fund, overseeing investments in logistics, housing, health care and agricultural development. In this capacity he has served as Chairperson of the Boards of companies in Kenya, Tanzania and South Africa.
Cedric brings decades of organisational and governance experience in the public, private and non-profit sectors, and a good understanding of how to get things done in a team. This organisational experience has been complemented by coaching courses with CoachTrax in 2014, and the University of Cape Town Business School in 2016. Cedric has an Associate Coaching Certificate with the ICC.
Frances started as a Senior Software Developer with Thornhill Associates in October 2013, and was appointed Lead Developer in June 2015. Prior to this she worked as a developer at the IT section of the Spec-Savers Group as well as several software development firms in Gauteng and the UK.
From 20 years in the IT industry she has gained experience on a wide variety of systems and platforms, and looks to draw on this to select the best route forward for the Thornhill Systems.
She holds degrees in Computer Science, Applied Mathematics and Conservation Biology – after software development her passions are research and the environment.
Yongama is an experienced full stack web developer specialising in Back-end Development, with his key programming language being PHP.
He has worked in several different environments and team sizes, from leading ad/digital agencies to Development houses large and small.
Yongama joined Thornhill in March 2021 as a Software Developer, and feels he is going to learn a lot from Thornhill as it is way outside his comfort zone.
He is also a Techie who loves gadgets and opening things up just to put them back together again.
In February 2010 Wendy joined Thornhill Associates as an administrator. She is responsible for administering online projects for clients, assisting with marketing activities, and supporting the coaches and consultants.
Wendy also has 20 year’s work experience from Wits Business School, where she was responsible for managing high profile WBS executive programmes.
Marilyn joined Thornhill in August 2018 as an Administrator bringing experience in administration and customer service, as well as a BA degree in Communication Science and a BA Honours degree in Media Studies.
She is extremely passionate about organising and promoting excellent customer service.
Marilyn enjoys travelling and also loves being outdoors. She participates in adventurous sports like trail running, hiking, canoeing and mountain biking, in between raising an equally adventurous and energetic tree climbing five year old.
Stacey joined Thornhill in June 2020 as an Administrator; she brings with her years of experience as an office admin manager. Stacey has a BCom degree in Intrapreneurial Management and is currently furthering her studies in Human Resource Management.
She is an enthusiastic organiser, who strives to be of service to others.
Apart from her administrator role, Stacey is the co-founder of a manufacturing company producing industrial energy saving thermal covers.