Jim Penman, the entrepreneur behind the Jim's Mowing franchise empire, has sparked debate with a contentious claim that dopamine overstimulation — driven by social media, junk food and other modern indulgences — is a key reason why Australians are having fewer children.
The Dopamine Theory Behind Australia's Birth Rate Crisis
Penman, who is also a candidate in next month's Victorian state election running under the Libertarian Party — formerly the Liberal Democrats — lays out his argument in a new book. He contends that contemporary life is flooding human brains with dopamine to such a degree that people lose interest in the more fundamental rewards of family life.
"The brain becomes adjusted. It becomes adjusted to this surge of dopamine and it becomes less sensitive," Penman said. "Ordinary things of life like family, children, work, faith, community become less and less appealing."
He points to social media, junk food, alcohol, pornography and sex as among the key sources of this overstimulation, arguing the solution lies in less instant gratification and greater personal discipline.
Australia's fertility rate has fallen to just under 1.5 children per woman — well short of the 2.1 replacement rate considered necessary to maintain a stable population without migration. Penman, himself a father of ten, acknowledges his view is outside the mainstream. "It's a very controversial take because it's not the normal take," he said.
Demographers Push Back on Single-Cause Explanation
Population experts have been quick to challenge Penman's thesis, arguing it oversimplifies a deeply complex social trend.
Dr Liz Allen from the Australian National University was pointed in her response. "Let's be clear here. Australians are not foregoing children because they are hedonistic and selfish," she said, adding that housing affordability, economic insecurity, gender inequality and uncertainty about the future are all significant contributing factors.
"Declining total fertility rates cannot be pinned down to one thing," Dr Allen said.
Her comments reflect a broader consensus among demographers that decisions around having children are shaped by a wide range of structural and economic pressures — a reality that connects to wider concerns about cost-of-living pressures and household financial stress that many Australians are currently navigating.
A Franchise King Turned Political Candidate
Penman built Jim's Mowing into one of Australia's most recognisable franchise businesses before turning his attention to politics and writing. His candidacy for the Libertarian Party at next month's Victorian election gives his comments an added political dimension, with his birth rate theory forming part of a broader worldview around discipline, community and what he sees as the corrosive effects of modern excess.
Whether his dopamine hypothesis gains traction beyond the campaign trail remains to be seen, but it has already succeeded in reigniting public conversation about why Australians are choosing to have fewer children — and what, if anything, can be done about it.
