As you practise karate you"ll learn not only kicks & punchers, but how to use karate techniques in a defensive situation. Having said that, I think that, yes Shoto Kan karate is very effective for real life self Defense. Karate teachers you how to walk away from an uncomfortable situation with your head held high. The younger they start the more confident they become and bullying does not worry them.
Karate incorporates teaching more than just the physical aspect of defending oneself, but also develops the psychological attributes that govern an individual's ability to react and prevent this situations from accurring.