A lot of popular kids cartoons these days are made in England. One of the most popular ones is Peppa Pig. My own two daughters are nuts over this show so I've seen the accent effect first hand. I haven't noticed it so much in my youngest daughter, but the older one was certainly affected by too much Peppa when she was about 3. Well I am not alone as an American parent it turns out. Recently more and more parents in the US are reporting that their kids have started speaking in British accents, pronouncing tomato as To-mah-toe for instance, or pronouncing it Zeh-brah rather than ZEE-bra. The good news is that psychologists say the effect will wear off eventually and your kids will drop it. So I guess we can just enjoy how cute it is while they still have it. See this video for more on the subject.