If it seems that they are harder to potty train, it may be (I feel anyway) that they have their minds on so many things that it's just not as important to them as some girls who are just naturally more picky about things at this age. BUT you will also find some boys that train early because they have this picky personality and girls that train later because they are more concerned with the world all around them. My first son was easy, my second son 7 years later oh my goodness he was 3 or so (but I NEVER said a thing, I just worked with him) and then my daughter 3 years later trained herself before 2 by watching everyone else BUT night times took longer than the boys because she slept so deeply. The main thing is to let them see others go in a certain spot...the toilet and they will catch on and don't make them nervous is most important too. They're all so sweet after they've grown and you look back on this time. Just love them through it all.