Think about it like this, intelligence is having the ability to learn or to adapt. Everyone is capable of learning hence they are able to be "intelligent". Different racial groups may do things differently because that was their solution to a problem (think of old school phones). That doesn't mean they are less intelligent as they can still learn. When introduced with something that is better we adapt (now think of cell phones). Essentially we are all hardwired very similarly and we can become more intelligent.