"The positive is that my father instilled in me a profound and deep respect for the weapon."
Pitt's latest movie is set during the Second World War and stars the actor as the commander of a Sherman tank crew during the Allies' final push into Nazi Germany.
The father-of-six flew his family to filming locations in Hertfordshire and Oxfordshire.
He said that his 13-year-old son Maddox "knows so much about tanks that when we first started on the movie, I was asking him for information".
"He has an extensive knowledge developed on his own since he was young," he said.
Six-year-old Knox visited the set and, "loved the tank, and though he has no concept of war or what the tank's history is, he was so drawn to it. There is that inexplicable fascination that man has with machine".