Jim Penman’s Unusual Theory to Reverse Declining Birth Rates

Limiting sexual activity could increase birth rates, according to Jim Penman, the founder of Jim’s Mowing. In a new book, he argues that modern stimuli such as sex, drugs, parties, and social media have desensitized dopamine receptors, reducing interest in faith, community, marriage, and having children.

Penman writes in “The Birth-rate Crisis: the Hidden Catastrophe in the Global Decline” that “scientific interventions may become necessary” to address falling birth rates.

As CEO of Jim’s Group, the largest franchise in the southern hemisphere with annual turnover exceeding $1 billion, Penman has invested millions in epigenetic research. He believes gene editing, pharmaceuticals, or pheromones could restore dopamine sensitivity and solve the crisis.

Global birth rates have fallen below the replacement level of 2.1 births per woman in most countries. Australia’s rate stands at 1.48.

Government initiatives such as Australia’s baby bonus have failed to alter this trend, Penman notes.

“We’ve proposed a more controversial possibility: that the birthrate crisis may ultimately require a biological solution and not just a cultural one,” Penman writes.

“My research team is actively investigating such treatments. Technological and medical advances may eventually make it possible to alter how the brain responds to reward and stimulation.”

“Immediate benefits could include improvements in addiction, anxiety, depression, motivation, and self-control. In the process, the birthrate crisis itself might largely disappear.”

Penman has 10 children and said he “would dearly have liked more.”

He is running for the Libertarian party in Victoria’s November election, but his views do not align neatly with the global “pro-natalist” movement. That movement is predominantly right-wing in the United States, advocating for traditional families and reduced immigration.

Elon Musk has called the collapsing birthrate “the biggest danger civilisation faces by far.” The SpaceX CEO and father of 14 retweeted a post about Australia’s fertility rate on June 7, commenting, “They are disappearing.”

Late activist Charlie Kirk urged people to “get married, have kids, and stop partying into oblivion.” U.S. Health Secretary Robert F. Kennedy said the “fertility crisis [is] a threat not only to our economy [but] to our national security.” Donald Trump has called himself the “fertilisation president” in an effort to encourage more births.

In Australia, Nationals leader Matt Canavan has called for “more Australian babies.”

Research indicates that women’s liberation, education, and access to contraception have contributed to declining birth rates. Women having children later in life tend to have fewer and face greater fertility challenges.

Social and economic policies also play a role. Polling for Nine Newspapers found that the most common changes people said would encourage more children include remote work policies, extended parental leave, free or heavily subsidized childcare, and affordable family housing.

Penman, however, argues that financial reasons “don’t fully explain the scale and consistency of the decline.”

He identifies sex, sex addiction, pornography, social media, gambling, drugs, alcohol, tobacco, calorie-dense food, and caffeine as factors disrupting brain chemistry.

“Our brains have been so bombarded by surges prevalent in the modern world that we’ve become far less sensitive to dopamine,” he writes.

Conversely, religious communities such as the Amish and Mormons, which discourage gambling and heavy drinking, tend to have higher fertility rates, Penman says.

“Another shared factor is the strong discouragement of sexual activity outside marriage, including masturbation,” he writes.

“Marriage also tends to be both early and near-universal, at least compared to wider society.”

He acknowledges it is difficult for young men with normal sex drives to avoid “any form of sexual outlet,” but says any reduction could help. He describes his own experience as having had a “profound effect” on his character.

“For five years after reaching puberty, my sole sexual outlet was nocturnal emissions, more commonly called wet dreams,” he writes.

“Lack of sexual outlet meant that I had fewer of the surges that desensitise brains to dopamine, so my brain could have become unusually sensitive to its effects. And because it happened at a young age when my brain was plastic, this effect would be enduring.”

He argues that limiting sexual activity is an effective way to increase dopamine sensitivity, and that “even within marriage, frequent sexual activity may have negative effects,” but these are offset by benefits such as strengthening the marriage.

As more women pursued education and careers, often delaying marriage, there were “more premarital relationships, wider use of birth control, and more open discussion of sexuality,” Penman writes.

He points to the 1920s as a key turning point.

“Cultural trends such as the emerging image of the ‘modern woman’, jazz, film, and consumer goods reflected these changes,” he writes.

“Lively parties, especially combined with alcohol and drugs, are also attractive.”

Penman argues that limiting or forbidding such activities makes the brain more sensitive to dopamine, making everyday activities more pleasurable and reducing the urge to seek dangerous stimulation like alcohol, drugs, gambling, pornography, and promiscuous sex.

There is ample evidence linking these activities to dopamine highs and lows.

Dr. Anna Lembke, author of “Dopamine Nation,” has warned that smartphones are turning people into dopamine addicts and causing depression.

She explains that the brain compensates for instant gratification from pleasurable stimuli by “bringing us lower and lower and lower,” and advises stepping away from phones and doing “things that are hard” for delayed pleasure.

Online advice often promotes “digital detoxing” to restore dopamine balance, though the science remains nuanced and mixed.

Penman goes further, arguing that medical treatments, not just digital detoxing, may be the solution. His research company, Epigenes Australia, is exploring ways to mimic calorie restriction to reset the brain.

He notes that female rats with restricted food in studies are more attentive to their young, and he writes that scarcity could “reduce overstimulation and restore sensitivity to everyday rewards.”

Rats exposed to “the soiled bedding of calorie-restricted rats” became more “exploratory,” he writes.

Penman says his team plans similar experiments with humans using sweat rather than urine, but regulations in Australia make it prohibitively expensive. “It’s one reason we’re moving much of the research to China,” he says.

He is also interested in exploring GLP-1 drugs such as Ozempic or semaglutide, which have been shown to reduce interest in alcohol, smoking, and gambling as well as food.

Scientists are still studying how GLP-1 medications affect people, including potential “emotional flatness.” Neuroscientist Paul Kenny of the Icahn School of Medicine in New York recently said these drugs could affect emotions and social interactions.

A third avenue is gene editing. Penman points to CRISPR technology, suggesting that epigenetics could mimic the effects of calorie restriction, making marriage and children more appealing.

“Over time, the birthrate crisis could begin to reverse naturally,” he writes.

“The Birth-rate Crisis: the Hidden Catastrophe in the Global Decline” is set for self-publication in October, with proceeds funding further research.