Ben Stiller's father "really cared" about him

Appearing with his sister Amy on YouTube series 'Star in the House', Ben said: "He wrote me this long letter about life and why it's important to stick things out.

"It got very philosophical. Reading it now, it was a beautiful thing. He really cared."

The siblings also noted that Jerry was "so not like" his 'Seinfeld' alter ego, the angry Frank Costanza.

Ben and Amy talked about how much "fun" it was growing up with famous parents, particularly as Jerry and their mother Anne Meara, were in the spotlight during a different era.

Amy said: "It was fun you know? It wasn't like they were movie stars. I think in the 70's there was a such a difference between TV and movies so it wasn't like that kind of famous.

"hey were also the kind of people who people on the stoop would be like 'Hey Jerry, hey Anne!'

"It had that kind of feeling to it but I think when we're starstruck...we were so excited going on the set, I remember we snuck on the site of 'St. Elsewhere' and we were like 'stat!' we were running around, it was exciting.

Ben added: "Because it was our lives, we didn't know anything else but we didn't think they were super famous people...

"We'd go to see play with them and we'd always go backstage but to me, the exciting part was when they would do something in LA...It was always fun to go to the night club.

"Remember when they played the Persian Room Amy?...The Persian Room was a night club that was in the Plaza Hotel...And the did a lot of summer stock also. We used to love going on the road with them also in the summers."