Are children's helmets with styling less safe? In a couple well received answers to a recent question it is suggested that sliding on the road is an important consideration for helmets.

A number of children's helmets now are available with spikes or ears or fins that would seem to have a meaningful impact of the ability to slide.

Are these helmets less safe?
Sad to say, I think with children the main injury mechanisms are falling off their bike at low speed or getting hit by a car. Both are blunt force trauma that the helmet can mitigate with little sliding. 

Contrast against a road or mountain bike going downhill at 50 kph and wiping out at a corner.