Julian Lennon wrote the Foreword for his mother’s book, “John”. It's Cynthia Lennon's biographical account of her involvement with John Lennon (Hodder & Stoughton, 2005).
... ... While Dad was fast becoming one of the wealthiest men in his field, Mum and I had very little and she was going out to work to support us.”
Nine years after Primal Therapy, in the spring of 1979, John Lennon invited Julian to the United States for his sixteenth birthday, in the Easter holidays. This is what Cynthia Lennon wrote in her book about what happened [page 356 in the paperback edition].
One incident in particular did him lasting damage. The whole family had been having fun, making Mickey Mouse pancakes and fooling around, when Julian giggled. John turned on him and screamed, ‘I can't stand the way you fucking laugh! Never let me hear your fucking horrible laugh again.’ He continued with a tirade of abuse until Julian fled once again to his room in tears. It was monstrously cruel and has affected him ever since. To this day he seldom laughs.”
- Bing Crosby and his sons – violent beatings took their toll.
There's a http://debunkingprimaltherapy.com/ website, to which I contributed some book quotes, including the ones on this page.