Mac Leaf responds to “Dr Caroline Leaf – Serious Questions, Few Answers”

Mr Mac Leaf, the husband of Dr Caroline Leaf, kindly took the time to respond to my series of posts on the teachings of Dr Leaf at Kings Christian Centre, on the Gold Coast, Australia, earlier this month.  As I had intended, and as Mr Leaf requested, here is his reply, complete and unabridged.  My further response is posted here.

In the interests of healthy public debate, and encouraging people to make their own informed decisions on the teachings of Dr Leaf, any comments regarding the response of Mr Leaf or my reply are welcome provided they are constructive.

Hi Dr C. Pit,

It is a pity you did not seek to clarify the comments you have posted above with us before you posted them. We hope you allow our comments to be displayed so that your readers can make informed decisions and not to judge Dr Leaf as you have done without getting accurate information. By your comments it is obvious that you have not kept up to date with the latest Scientific research.

Dr Leaf can call herself a Cognitive Neuroscientist because of her field research (published in peer evaluated Journals) …see the Science articles in the media/downloads section at If you require, we can also send letters from her peers in the field of Neuroscience

She also developed the Geodesic Information Processing model theory.

Yes she does read a lot as the field of Neuroscience is constantly evolving and one has to be as informed as possible.

Some research links re the correlation between illness and thought are presented in Dr Leaf’s November the 30th blog at…blog. There are many more statistic correlation research links.

Dr Leaf has listed references differently in the different books and has a full list of references in the ‘thought life’ section at The references were listed simply in that book for the lay person. This is an accepted literary format for the lay person. Subsequent books have fuller references.

The mini brain in the heart research can be found at

Heartmath and Dr Don Colbert both reference the effect of ANF

The wired for optimism bias research has been evidenced by various scientific researchers
For easy access to this research please see the Google links to TED talks and Time Magazine’s article.

Please send us your E-mail address so that we can send you further documentation.

My name is Dr Peter Amua-Quarshie and I am presently a full-time Adjunct Professor (lecturer) at the University of Wisconsin-Stout in Menomonie, Wisconsin. I have a B.Sc (Hons) in Medical Sciences (specializing in Neuropathology) and a Masters of Public Health (MPH), both degrees from the University of Leeds (UK). Additionally I have a medical degree (MB ChB) from the University of Ghana Medical School, Accra, Ghana, and a Master’s of Science (MS) in Behavioral and Neural Sciences from Rutgers University, Newark, New Jersey. I started teaching anatomy in the University of Leeds Medical School in 1996. I have taught Neurochemistry to graduate students and Neuroscience to undergraduates at Delaware State University and the University of Wisconsin respectively. I have known Dr. Caroline Leaf since 2006 and have worked closely with her since 2008 on various projects in the field of cognitive neuroscience.
Caroline Leaf received her training in Communication Pathology (BSC Logopaedics) at the University of Cape Town, South Africa. The University of Cape Town has produced many outstanding graduates, including Max Theiler, a Nobel Prize laureate in Physiology or Medicine and Christaan Barnard, the first person to successfully transplant a human heart. Caroline Leaf was a contemporary to the eminent neuroscientist Henry Markram, director of the Blue Brain Project and the new one billion Euro European Union Flagship Project, the Human Brain Project. As well having to study the cognition, she had to endure the rigor of the first 2 years of the medical course, in which she had to study neuroanatomy and neurophysiology. Dr. Leaf also holds a Master’s degree and PhD in Communication Pathology from the University of Pretoria, South Africa. In her Master’s degree her dissertation concentrated on cognitive neuroscience of Traumatic Brain Injury (Closed Head Injury). In developing her groundbreaking Geodesic Learning™ Theory (brain-compatible learning) in her ground breaking PhD thesis, she examined cognition and neurobiology of thinking. The Geodesic Learning™ Theory has been implemented among approximately 100,000 students in South Africa with great success. I have personally helped implement her Geodesic Learning™ Theory in a School District in the USA and was able to demonstrate quantitative improvement in scholastics across the board among the students. She is widely published in journal, book, DVD, television and the internet in the field of cognitive neuroscience in South Africa, USA and other parts of the world.
I have discussed neuroscientific subjects with her for multiple hours many times and have been thoroughly impressed with her knowledge and insight in neurobiology. However what really thrills me is revelation God gives her about the brain. She is an example to me of a neuroscientist who glorifies God in her pursuit of understanding the brain, and who is able to demonstrate that we are truly fearfully and wonderfully made (Psalm 139:14).


Since 1985, Dr Caroline Leaf, a Communication Pathologist and Audiologist, has worked in the area of Cognitive Neuroscience. She holds a Bsc Logopaedics with focus on in Neuroscience, Neuronanatomy and anatomy, Communication Pathology, Psychology, linguistics and audiology) , Masters in Communication Pathology She specialized in Traumatic Brain Injury and PhD in Communication Pathology (TBI) and Learning Disabilities focusing specifically on the Science and neuroscience of Thought as it pertains to thinking and learning. She developed a Cognitive Neuroscientific theory called the Geodesic Information Processing Theory for her PhD research and did some of the initial research back in the 1990’s showing how using non-traditional techniques, based on neuroscientific principles of neuroplasticity and neuropsychological principles, that the mind can change the brain and can effect behavioural change as seen academically, behaviorally and emotionally. A large part of her research in recent years has been to link scientific principles with scripture showing how science is catching up with the bible.

She applied the findings of her statistically proven research in clinical practice for nearly 20 years and now lectures and preaches around the world on these topics. She is a prolific author of many books, articles and scientific articles. She has been a featured guest of Enjoying Everyday Life with Joyce Meyer, and LIFE TODAY with James and Betty Robison, Marilyn Hickey, Sid Roth and TBN Doctor to Doctor, amongst many others. She has her own show on TBN called Switch on Your Brain.

Her passion is to help people see the link between science and scripture as a tangible way of controlling their thoughts and emotions, learning how to think and learn and finding their sense of purpose in life.

Caroline and her husband, Mac, live in Dallas, Texas with their four children.

Dr Leaf’s Qualifications

Web page: has my full qualifications and links to the Universities where I studied

Dr Leaf’s Reference list

1. Leaf, C.M. 1985. “Mind Mapping as a Therapeutic Intervention Technique”. Unpublished workshop manual.

2. Leaf, C.M. 1989. “Mind Mapping as a Therapeutic Technique” in Communiphon, South African Speech-Language-Hearing Association, 296, pp. 11-15.

3. Leaf, C.M. 1990. “Teaching Children to Make the Most of Their Minds: Mind Mapping” in Journal for Technical and Vocational Education in South Africa, 121, pp. 11-13.

4. Leaf, C.M. 1990. “Mind Mapping: A Therapeutic Technique for Closed Head Injury”. Masters Dissertation, University of Pretoria.

5. Leaf, C.M. 1992. “Evaluation and Remediation of High School Children’s Problems Using the Mind Mapping Therapeutic Approach” in Remedial Teaching, Unisa, 7/8, September 1992.

6. Leaf, C.M., Uys, I.C. and Louw, B. 1992. “The Mind Mapping Approach(MMA): A Culture and Language-Free Technique” in The South African Journal of Communication Disorders, Vol. 40, pp. 35-43.

7. Leaf, C.M. 1993. “The Mind Mapping Approach (MMA): Open the Door to Your Brain Power; Learn How to Learn” in Transvaal Association of Educators Journal (TAT).

8. Leaf, C.M. 1997. “The Mind Mapping Approach: A Model and Framework for Geodesic Learning”. Unpublished D.Phil Dissertation, University of Pretoria.

9. Leaf, C.M. 1997. “The Development of a Model for Geodesic Learning: The Geodesic Information Processing Model” in The South African Journal of Communication Disorders, Vol. 44, pp. 53-70.

10. Leaf, C.M. 1997. “The Move from Institution Based Rehabilitation (IBR) to Community Based Rehabilitation (CBR): A Paradigm Shift” in Therapy Africa, 1 (1) August 1997, p. 4.

11. Leaf, C.M. 1997. ‘”An Altered Perception of Learning: Geodesic Learning” in Therapy Africa, 1 (2), October 1997, p. 7.

12. Leaf, C.M., Uys, I. and Louw. B., 1997. “The Development of a Model for Geodesic Learning: the Geodesic Information Processing Model” in The South African Journal For Communication Disorders, 44.

13. Leaf, C.M. 1998. “An Altered Perception of Learning: Geodesic Learning: Part 2” in Therapy Africa, 2 (1), January/February 1998, p. 4.

14. Leaf, C.M., Uys, I.C. and Louw, B. 1998. “An Alternative Non-Traditional Approach to Learning: The Metacognitive-Mapping Approach” in The South African Journal of Communication Disorders, 45, pp. 87-102.

15. Leaf. C.M. 2002. Switch on Your Brain with the Metacognitive-Mapping Approach. Truth Publishing.

16. Leaf, C.M. 2005. Switch on Your Brain. Understand Your Unique Intelligence Profile and Maximize Your Potential. Tafelberg, Cape Town, SA

17. Leaf, C.M. 2008. Switch on Your Brain 5 Step Learning Process. Switch on Your Brain USA, Dallas.

18. Leaf, C.M. 2007. Who Switched Off My Brain? Controlling Toxic Thoughts and Emotions. Switch on Your Brain USA, Dallas.

19. Leaf, C.M. 2007. “Who Switched Off My Brain? Controlling Toxic Thoughts and Emotions”. DVD series. Switch on Your Brain, Johannesburg, SA.

20. Leaf, C.M., Copeland M. & Maccaro, J. 2007. “Your Body His temple. God’s Plan for Achieving Emotional Wholeness”. DVD series. Life Outreach International, Dallas.

15 thoughts on “Mac Leaf responds to “Dr Caroline Leaf – Serious Questions, Few Answers”

  1. Pingback: Dr Caroline Leaf – Contradicted by the latest research | Dr C. Edward Pitt

  2. It was really good to hear your arguments around Dr Caroline Leafs work. It proves that the work is worth looking deeper into. She won’t be able to minimise every possible bias. You had some good points and it has helped me to refine how I go about doing my own research and how to present that. Dr Leafs work has been very helpful to me on a personal level, including inspiring me to attempt my own career in psychology and further research into the message that she is trying to convey.
    Any good Dr has peers trying to pull apart their theories, this is the only way humanity will come to any conclusions about how we are wired and how we can function to our full potential.
    Though not everyone gets to go to school/university and do their own research having all this work out simply and in a way that I as a currently uneducated person can understand makes her life work worth more than if it just went into a journal only to be read by peers and pulled apart to try and discover some level of truth.
    Perhaps your approach could be to look at the work she has done and see what benefit it has for “lay” people.
    what are the negative affects of an uneducated person picking up this book switch on your brain and working through it? Why waste time trying to fight against someone’s research and claims ? What are you actually trying to achieve?
    People spend their lives coming up with theories that remain theories, Dr Leaf is using what she knows and the success stories she has seen come to pass to educate others to free their minds.
    I haven’t delved into the percentages from either her or you around illness being related to stress and I am certainly not trying to be scholarly in any way, I just find that seeing someone passionate about people’s health and wellbeing and not cutting parts of their brain out or using medication or electric shocks to treat people much more encouraging and makes the psychology world seem more beneficial than hurting a few people through experimentation only to come to no avail.
    However as previously mentioned it’s great to see that other Drs are paying attention to her work. There must be something worthwhile paying attention to.
    They say research isn’t good research until it’s been picked a part by peers..
    My suggestion to Dr Leaf and her husband would be to note that whatever you’re doing is working because other Drs are paying attention but also maybe it creates opportunity for you to see a different perspective?? Though you are just a couple of people and probably need at least a hundred other researchers to address some of the points he brought up.
    Anyway I’m sitting in a cafe having done no research around any of this, just wanted to say Dr Leaf you’re doing an amazing job and Dr Pitt thanks for picking these points out because it has opened my eyes to narrowing down my own research and working with a smaller group than trying to change the world 😃

    • Jacquie,

      Thanks for your insights and opinions.

      I’m glad that Dr Leafs work (and perhaps my critique) has helped you in finding your path. I wish you all the best in your chosen study and vocation. Psychology helps a lot of people, so I think you’re on to a good thing.

      I can’t speak for Dr and Mr Leaf, but if you feel that Dr Leafs work has benefitted you as a lay person then that’s good. There are many other appreciative testimonies on Dr Leafs social media pages.

      And you’re right in suggesting that any good theory needs to be pulled apart to prove that it’s robust, that’s how good science works. Though it’s interesting to note at this point that Dr Leafs social media moderators actively censor dissenting comment, and block those who express alternative views from commenting. This didn’t just happen to me, but to others who have shared this in comments on this blog. One wonders why Dr Leaf has allowed her moderators to do this, since it only stifles free speech, critical appraisal, and the progress of good science.

      You made a very reasonable suggestion to look at the work Dr Leaf has done and see what benefit it has for “lay” people, and as it turns out, I’ve done so just recently. I reviewed Dr Leaf’s published research including her PhD thesis and a study on the effectiveness of her “Switch On Your Brain 5-Step Learning” module. I think it’s fair to say that Dr Leaf’s published trials have shown that her programs are ineffective. I understand that sounds harsh, so let me clarify.

      In order to eliminate bias, controlled trials with adequate statistical analysis need to be done. When Dr Leafs published results are reviewed in the cold light of day, the change that’s seen is negligible, if indeed there is any change at all. The results in her Dallas study appear to be mostly due to chance. Her PhD research showed negligible difference between the controls and the intervention. There may have also been some negative effects. For a full analysis, I suggest that you review my post “The TEDx Users Guide to Dr Caroline Leaf” (

      You then ask three very important questions: “what are the negative affects of an uneducated person picking up this book switch on your brain and working through it? Why waste time trying to fight against someone’s research and claims? What are you actually trying to achieve?” I am the first to admit that there is no direct evidence that Dr Leaf’s research or teaching has done direct harm, although like I said earlier, Dr Leaf’s moderators suppress dissenting opinion and comment, so who knows. However, if Dr Leaf’s teaching is ineffective, then at the very least, those who have a mental illness and who attempt Dr Leaf’s tools and programs are wasting money and time on something ineffective, when they could be engaging in effective management. Further, in her 2013 book, Dr Leaf suggests that taking anti-depressants for the treatment of depression “is biblically and scientifically incorrect.” (Leaf, C. M. (2013). Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health. Grand Rapids, Michigan: Baker Books: p32) Should someone with depression take Dr Leaf’s statement at face value, then there is a real possibility that they would stop their medications and relapse. So Dr Leaf’s teaching may divert someone from receiving useful therapy, and potentially may have serious consequences.

      Hence, why I think that challenging her research and claims is time well spent. Mental health care is critical to our society and the church, which makes it even more imperative that the teaching of the most influential speaker on mental health in the church is critiqued, as her teaching is going shape the direction of the church’s handling of mental health care into the future.

      It may seem esoteric to debate the correctness of statistics, but both the discrepancy between Dr Leaf’s numbers and current estimates, and how she arrived at those numbers, speak to her ability to interpret research and arrive at appropriate conclusions, and thus, how we should judge her other hypotheses.

      If you haven’t done so already, I would suggest that you read my book “Hold that thought: Reappraising the work of Dr Caroline Leaf” (iBooks = or Smashwords = which gives a much more in-depth review of Dr Leaf’s work and the evidence for and against it. I believe that there are a number of critical flaws with Dr Leaf’s teaching, but if you still agree with Dr Leaf after reviewing all of the evidence, then that’s fine. I only ask that people review Dr Leafs work, and my own, with an open mind.

      All the best with your future studies, and again, thanks for sharing your opinion.

      • Hi Edward

        I find it very interesting that you spend so much time on your opinion regarding Caroline Leaf. Why don’t you rather focus your time on stating what you believe should be done to make this world a better place!

      • Hi Marisa,

        Thanks for your comment.

        Sharing my opinion on Dr Leaf *IS* what I believe will make the world a better place. I believe the majority of Dr Leaf’s teaching is factually inaccurate and misleading, and has the very real risk of causing harm.

        I’ve gone to great lengths to justify my opinion scientifically rather than make baseless accusations. I have no problem if people disagree with me, so long as they have objectively considered both sides of the debate before coming to their conclusions.

        I’ll say again, for the record, that I’m not criticising Dr Leaf as a person, and I’m not questioning her motives, which I believe to be genuine. But misinformation with the best of intentions is still misinformation.

        If you have any specific issues about what I’ve written on Dr Leaf, feel free to raise these and I’ll willingly discuss them.

        All the best.

  3. I would like just to note that neither mental health care or society has been given the mandate to care for the soul needs. Talk about ineffectual.

  4. I believe strongly in Dr. Caroline Leafs teachings because although I just found her on facebook earlier this year the way she teach I have been learning for years. My brain work the same way as she teaches the brain work. I keep up a continual internal dialog with the Holy Spirit as she teaches and it works to keep your thought life under control. Stop fighting against what she say (being so technical) and try to learn something that can change your life as well as save it. I love you Dr. Caroline, Vanessa

    • Thanks for taking the time to comment Vanessa. Your feelings for Dr Leaf are touching, and your opinions are common amongst Dr Leaf’s ardent supporters.

      It’s not my place to tell you what to believe, that’s entirely up to you. If you want to believe Dr Leaf’s teaching, I’m not going to argue. So long as you can honestly say that you have considered both sides of the debate.

      Dr Leaf is charismatic and engaging, but spinning a good story isn’t necessarily the same as speaking the truth. So perhaps it’s Dr Leaf who should stop fighting what I say and try and learn something from me?

      Like I said, you can believe what you like, but I’m confident that there’s nothing I can learn from Dr Leaf, and I am supremely confident in my salvation as my faith is in God’s word, not Dr Leaf’s version of it.

      All the best to you.

      • Dr. Pitt

        This is my first time commenting on any type of forum. I read the things you wrote about Dr. Caroline Leaf, I read her husband’s response and I read comments that a view wrote to you supporting Dr. Leaf with attacking you or disrespecting you. What you have presented my or may not be true, (I have not had an opportunity to check it out) but you tone in your writing and response to those who seem to support her seems a little sharp and spiteful. Makes it seem more of a personal attack against Dr. Caroline Leaf and not, constructive criticism. Bringing awareness to improper doctrine is very important. But how you bring that awareness is just as important. If you placed all the accusations concerning the accuracy of her findings without contacting her and sharing your concerns with her and giving her an opportunity to address those concerns, seems unprofessional. Also, Dr. Pitt is your book about Dr. Leaf free?

      • Hi Monica,

        Thanks for taking the time to raise those very important points.

        I confess, I’m very passionate about this subject. Having experienced mental ill-health personally, living with it in my family, and professionally seeing people every day who struggle with the profound despair and disability that mental ill-health brings, I have become a very strong advocate for those suffering from mental illness and their families.

        I’m self-aware enough to know that sometimes this zeal can spill over too much into what I write, which some people will judge to be personal criticism of Dr Leaf. But I’m also aware that I could be as bland and unemotional as humanly possible, but people would still interpret my disagreement with Dr Leaf’s teaching as something personal against her. Though on the other end of the spectrum, I have also had a fair degree of support as well. So I guess a lot of how my writing is perceived is in the eye of the beholder.

        From my point of view, it’s my intention to fully debunk and rebut Dr Leaf’s teaching and ‘scientific’ claims, without criticising her personally. That’s how good science works. If I do slip into personal criticism, then I will rewrite that post or said-portion.

        For the record, I did approach Dr Leaf as directly as I could after I heard her the first time. My concerns were sent through to the senior pastor of the church who hosted her, who kindly forwarded my concerns to her. But I also wanted to start a public discussion on Dr Leaf’s teaching as I had serious concerns about what she taught, concerns that were not publicly mirrored. Instead of Dr Leaf replying to me directly, the reply came from Mac Leaf, who chose to publicly criticise and dismiss my concerns (quite arrogantly in my opinion) on my blog post. That was a little over two years ago. In my reply, I made an offer that Dr Leaf was welcome to reply to anything I said, and I would publish it, in full and unabridged. The offer I made then still stands. I’ve made further offers – I will meet with Dr Leaf face to face, in private, in any Australian city that she chooses. She’s yet to take me up on this offer as well. Indeed, when Dr Leaf preached earlier this year in the city in which I live, I went up to her afterwards to shake her hand and introduce myself but was blocked by her presidential style security. So I feel as though I’ve made every effort to come to her directly with my concerns, all of which have been ignored or rebuffed to date. The offer to meet and the right of reply still stands if Dr Leaf wants to take the next step. The ball is in her court.

        Finally, yes, my book is free but is only available in electronic forms –
        Smashwords =
        iTunes =
        Web =

        Thanks for your willingness to discuss your concerns. I appreciate all opinions here. In the future, if you do think I step over the line from strident critique of Dr Leaf’s ideas to criticism of Dr Leaf herself, please shoot me a comment and I’ll definitely review it.

        All the best to you.

  5. I hardly see you as qualified to install yourself as a critic of Dr. Leaf or any expert in her field for that matter. Here is an excerpt from your own “about” tab on this rather trollish blog of yours;

    “Since attaining his GP Fellowship in 2005, he has gained experience in many and varied areas of medicine including Skin Cancer Medicine, Cosmetic Medicine, Aged Care, Sexual Health and Family Planning, and is a regular question writer and examiner for the Royal Australian College of General Practice.”

    Laughable that you expect someone of Dr. Leaf’s stature to engage you in your so called search for the truth and mission to expose apostasy. This blog is nothing more than a sad diabolic attempt to troll for a ride on a bright vessel of revelatory insight such as Dr. Caroline Leaf who by her diligence and loving heart has brought hope and healing to many hundreds of thousands.

    Lets just be honest and expose this blog post of yours for what it truly is, trolling… Maybe you should be honest with yourself and with God about your true motives which seem evil as evidenced by your snarky response to Dr. Leaf’s husband Mac’s gracious and lengthy informative complete response. I think you are coming from a wounded bitter critical heart and therein lies your motivation to gain attention in this fashion. I would respectfully recommend you focus on your GP fellowship and go back to your work in skin cancer, plastic surgery, aging, sexual health and family planning. There are more than enough elderly who need cosmetic surgery and Rx’s for viagra and other meds for ED. Stick to general practice medicine and being a question writer in that field and leave the deep spiritual stuff for qualified individuals.

    • Dear Allen,

      Thank you for your uplifting encouragement.

      There are many ways that I could respond to your comment … “Excuse me sir, but there appears to be a beam in your eye” … “Trolling hey. Takes one to know one” … “There’s a wounded heart here, but it’s clearly not mine”, etc. …

      Actually, you’re the only person to accuse me of trolling since I started this blog a couple of years ago, and since there’s been more than 60,000 views in that time, it seems that you’re 60,000 to 1. And for the record, I’ve been called a lot worse.

      Personally, I’m not bothered by what you say here. I’m not here to win an argument, neither am I here for attention. And like it or not, I am more than qualified to comment on Dr Leaf’s work. If you would rather make snide comments on what you perceive as my weaknesses instead of critically examining the science behind my critique of Dr Leaf, whom you seem to blindly follow, then be my guest.

      Though next time you want to try and defend the “bright vessel of revelatory insight”, I suggest you try using your brain. If you really think I’m an apostatical troll, you’re more than welcome to criticise me, but prove it first by actually demonstrating why my work is wrong. I suggest you use references. If you can prove that I’m wrong and that Dr Leaf is right, then I’ll formally apologise, in writing, on this blog.

      If I’m right … well, perhaps you’ll think twice before launching into a slanderous hypocritical rant.

      All the best to you, and happy holidays.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s