Size-growth differences

I'm surprised at the differences in size and growth. By far the buff orps are the largest, and the boldest, and friendliest, two of them love to cuddle down into my palm. The RIRs are second in the size department, but nowhere near as friendly, although they are bold. The EEs or Americuanas or whatever they are are third in growth, boldness, but not very friendly. Fourth in growth are the barred rocks, they are neither bold or friendly, they are very skittery, but not as skittery as the so far much smaller golden laced wyandottes. They seem to be the slowest growers, very scared, couldn't find bold in the dictionary just not happy at all with my presence. I'm jut noting the differences, they're all beautiful to me. I'll take more pictures this Wednesday, their second week birthday.