Electric guitars have no air resonance cavity. Hence there is no body of air to be affected by guitar body vibration. But there is still the guitar body vibration, sympathetic to string resonance. Whereas in theory at least (given the transducers - pickups - are accurate) an electric guitar can have more of a "string sound" than an electric guitar, this body vibration is defined by the guitar's materials and design.

Different types of wood will have different responses; e. g. mahogany will generally have more of a low-midrange growl (as you can hear with an SG), basswood will be mostly midrange, alder, being a birch relative, will give an even response across the whole range (some call this "bright", but it really is just "not dark").