By any measure, they were curious family outings.
After dark, 12-year-old Clyde Hertzman and his elder brother Owen would sprint, jog and walk the side streets of Vancouver's upper-middle-class Oakridge neighbourhood. Taped to their chests were portable EKGs.
Their mother, Eileen, drove beside them, while their father, an eminent cardiologist, sat in the back, collecting signals from the boys' varying heartbeats on a reel-to-reel tape recorder.
There was a purpose to Victor Hertzman's ordering of his sons about. By measuring recovery rates from different stresses on their hearts, he sought to strengthen his belief that carefully prescribed activity was better for heart patients than rest. Now accepted treatment, that was heresy in the early 1960s.
Their year or so as human guinea pigs left the brothers without chest hair, but the lesson of his father's homespun experiment was not lost on young Clyde.
The power of evidence to drive change formed the bedrock of a long, remarkable, groundbreaking career, one that ended suddenly on Feb. 8, when Dr. Hertzman died at the home of friends in London, England, of an apparent heart attack. He was six weeks shy of his 60th birthday.
His death prompted an outpouring of accolades from shocked colleagues who revered him, renowned researchers who marvelled at his work and organizations that embraced his conclusions.
Passionate, relentless in the pursuit of truth, boundlessly energetic and possessing a brilliant, incisive mind, Dr. Hertzman dramatically altered the way Canada and increasingly the world thinks about the importance of early childhood.
In study after study, he demonstrated that the circumstances of a child's first few years are critical to future development, right through to old age. Low socioeconomic status, poor parenting, stress, lack of stimulation before one turns five could stunt a person's life forever.
The theory was not new, but not until teams headed by Dr. Hertzman amassed broad-based data identifying the risk levels of children entering the school system did it really take root.
As his research evolved, Dr. Hertzman coined the now widely used term "biological embedding" to describe how early environment is more a determinant of a child's future behaviour than genetic makeup.
"Early social experiences get under the skin to set a lifelong trajectory for health and well-being," explained Alan Bernstein of the Canadian Institute for Advanced Research. "Clyde played a central role in creating a framework to understand that."
His worldwide reputation was recognized in 2005, when the World Health Organization set up an international commission on the social determinants of health. Dr. Hertzman was asked to head the section on early childhood development.
"He wasn't the first person to show that it is important for adult health, but Clyde made it important," said commission chairman Michael Marmot of University College in London. "He synthesized the material. He showed how important it was in a population health context."
In 2010, the Canadian Institutes of Health Research named Dr. Hertzman "health researcher of the year," providing him with a grant of $500,000.
At the end of December, he was named an officer of the Order of Canada, an award that touched him deeply.
"It was recognition," said his partner, Marcy Cohen. "When you are someone passionate like Clyde, who doesn't dress in suits, and doesn't always win the favour of the establishment, you suffer from that at times. The Order of Canada was extremely important to him."
A professor for more than 25 years in the School of Population and Public Health at the University of B.C., Dr. Hertzman also held a number of prominent research chairs and directed the Human Early Learning Partnership, comprising academics from six B.C. universities dedicated to leading-edge research on early childhood development.
Born March 24, 1953, Dr. Hertzman was the younger of two sons of Victor and Eileen, an accomplished pharmacologist.
The brothers were highly active teenagers, whether trolling for salmon along remote stretches of the West Coast, or, despite their short stature, tearing up the football field. At one point, Owen said, the pair sidelined Michael Campbell, brother of former premier Gordon Campbell and well-known financial analyst, with a crunching tackle.
As the turbulent 1960s ended, however, Clyde was caught up in hardline politics. At 17, hair down to his waist, he moved into a collective house and joined the radical Vancouver Liberation Front, scourge of mayor Tom Campbell, who threatened to unleash the War Measures Act against the ultraleft organization.