Despite the three year age difference, my two boys are surprisingly good friends. The youngest still doesn't talk (unless you consider a barrage of this great conversation: "On, on on on, ON!!!" (I REALLY need you to turn the light on, NOW!!!", or, "Aah dah dah dah, AASH?" (isn't it time to wash my hands, Mommy?)), so they don't really "play" yet, but they sure make each other laugh and are quick to offer love when something goes amiss.