^Steve Biddulph is exposed as getting his facts wrong - and is alleged to be refusing to answer questions on his evidence on the subject.
Last night, my husband took up the baton and tried to find out a bit more and cite sources. He discovered that Steve Biddulph may have made an honest (but nevertheless, totally inaccurate) mistake. It turns out that while there is no surge in testosterone at age four, there is a surge in Lutenizing Hormone, which creates the building blocks for testosterone, between the ages of 4 and 6. Effectively, Lutenizing Hormone builds the machine which WILL produce testosterone between the ages of 4 and 6, but that machine doesn’t get switched on until puberty. Here are his (brief) findings, with citations:
There is a rise in Luteinzing hormone between the ages of 4-6 in boys which drops again at around seven. The profiles for LH, FSH, testosterone and Estradiol are different for boys and girls. Lutenizing hormone stimulates leydig cell production of testosterone, it is curious that while there is an increase of LH in boys between 4-6 there is not a corresponding increase in follicle-stimulating hormone, testosterone, or estradiol during this period.
Debbie Guatelli-Steinbergy and Jennifer Boyce, “The Postnatal Endocrine Surge and Its Effects n Subsequent Sexual Growth” p663-681 in Preedy, Victor R. (editor) Handbook of Growth and Growth Monitoring in Health and Disease NewYork: Springer. (2012)
Lutenizing Hormone does not have an effect on behaviour, and the most likely reason for “challenging” behaviour at this age is developing independance and sense of self - this is the same for both boys and girls. Sadly, it looks like Steve Biddulph made a big mistake in mixing up LH and testosterone which has become accepted fact, when there is no basis for it, and right now, he isn’t owning up to it.^