They say that blood is thicker than water and the Horn family from Malalane, in Mpumalanga, does nothing to dispel the theory.
Johan Horn senior is dealer principal at Malalane Garage, a family business started more than 70 years ago, and has seen his three sons follow him into the automotive trade. Francois, Johan junior and Werner all hold executive positions in Malalane Garage, with Johan junior and Werner also sharing their fathers passion for motorsport and, in particular, cross country racing.
The passion for motorsport culminated in Johan junior and Werner this year winning Class T in the Production Vehicle category in the South African Cross Country Series (SACCS). It all started, however, in the early 1980s when Johan senior bought his first off road vehicle from the legendry John Smith.
"It was a single seater which I converted into a twin seater," said Johan.
"Mazda rotary engines were all the rage in those days so, naturally, I went the same route.
"The car did not have an auspicious start and engine failure ruined its debut on the Roof of Africa."
Johan senior raced the car for a few seasons on events like the Swazi Spa 500, the Kalahari Desert Race, the Trans Tongaland and the Barberspan. One memorable Barberspan race saw conditions so wet it was "like driving through rivers."
The car was subsequently sold and Johan senior then built the first Malalane Toyota Hilux in the late 1980s which he raced with good friend Jan Joubert doing the navigating. The Hilux was fitted with a 22R Turbo conversion and provided for another memorable race.
"The Toyota 1000 which ran from Vryburg to Pomfret and back, and in those days there was no such thing as a service crew," said Johan senior. "My 'service crew' consisted of my wife, Leoni, and the three boys.
"During the race Jan and I ran out of fuel and, unbeknown to us, my 'service crew' were stuck in thick Kalahari sand."
A friendly farmer eventually towed Leoni and the three boys out of the sand and "race crew" and 'service crew' were reunited after an anxious couple of hours. The Toyota served Horn senior and Joubert well with the 1991 season proving their most successful.
After a second place in Class 6 on the 1990 Gilo Engineering event, Horn and Joubert put together a string of impressive results in 1991. The pair competed in Class 5 in the national championship and podium finishes included third on the Mmbatho Sun, second on the Toyota 1000 Desert Race and another second place on the Bell Trans Tongaland.
With the advent of what Johan senior calls the professional era, he laments that much of the sense of adventure has gone out of cross country racing.
"Nowadays you have GPS and the RallySafe system and the cars are so much more sophisticated," said Johan senior. "The racing today is still highly competitive and much safer, but the sense of adventure that was experienced in days gone by is missing."
Horn is convinced, however, that a great deal of the success story that is cross country racing in South Africa is down to family participation.
"My wife and the three boys never missed a race and the backbone of cross country racing is still family participation," he said. "Grannies, grandpas, uncles, aunts, siblings and cousins are still an integral part of what makes cross country racing tick."
Horn is inordinately proud of the success Johan junior and Werner have enjoyed in motorsport. Both boys showed an early aptitude for off road and enduro motorcycling and in 2007 Johan junior designed and built a Toyota Land Cruiser.
"Unfortunately I crashed the Land Cruiser on its first test run," a rueful Johan said. "It was back to the drawing board, but in 2008 Werner and I started to campaign the Land Cruiser in national championship off road events.
"We started out in Class F, graduated to Class D and our apprenticeship was a tremendous learning curve."
A maiden victory on the Toyota 1000 Desert Race followed and the Horn brothers were regular Class D podium finishers. The brothers just missed out on the championship in 2013 and then decided it was time to move up a notch on the cross country food chain.
"We bought one of the Castrol Toyota Hilux championship winning vehicles and moved into what was then the SP Class in the Production Vehicle category,"
said Werner. "Once again we were in a learning curve, but Johan and I took a decision that we would learn to walk before we could run.
"It was the right move and as we grew in confidence we knew that on our day we could beat anyone."
The 2017 season saw the brothers win Class T three times - including the Toyota 1000 Desert Race in Botswana - and they arrived at the last event of the season needing only to finish to win the championship. Second on the Atlas Copco Gold 450 saw the Horn brothers stamp mission accomplished, after
10 years, across the Class T championship.
For the Horn family it proved that blood is thicker than water.