The 30-year-old will take over the armband from current skipper Phil Neville in the summer, when the latter moves on from the game.
Jagielka says that, despite contrasting styles with Neville, he is relishing the chance to become the Toffees' leader.
"Responsibility is something that I need," Jagielka told Sky Sports News. "I'm still a bit of a big kid when it comes to messing around - afterwards. Everyone says what a fantastic captain Nev has been, that he has been such a professional.
"People sometimes don't understand that. He conducts himself right in every aspect, on and off the pitch. Maybe I can be a bit juvenile at times. That's the character I am, that's the character he is. I'm sure that we will be very different captains, but hopefully we will have a very similar impact on the squad.
"I'm 30 now, not 16 and 17, so the time has come for me to grow up. If someone has got a problem, or they need help and advice, rather than hiding from it, I will try to help them out."
Jagielka joined Everton from Sheffield United in 2007.