Thanks to Thom for addressing, if in passing, human overpopulation during today's Free Speech TV program. Rarely does anyone in the media have the courage to do this. I'm a retired neuropsychiatrist and, now, arm-chair neuroscientist, who's written a free e-book PDF by the above title. Just Google the title. What I've discovered in my extensive literature searches fits with my 40 year experience in medical practice: population density stress is the basic cause of ALL human "diseases of civiization", none of which are found in traditional living hunter-gatherer populations. Furthermore, in the many animal crowding experiments done since the 1920's, but rarely widely reported, these animals reach a density and state of disruption of parenting behaviors beyond which ALL reproduction ends and the entire population goes extinct. Sperm counts among Western men have fallen by 50-60% over the past 43 years. Infertility among American couples has incresed 100% in 34 years: 8% in 1982, but 16.7% in 2016. At current rates of fertility loss, we may reach an extinction event as a species by 2,100. The only solution is as Thom described: empowerment of women. Only an immediate movement to voluntary one-child famillies can prevent a catastrophic extinction event. thanks, again, Thom, for this wonderful website.