I think there is some kind of correlation between early motor skills and G, though not a strong one. My most physically precocious child was walking at seven months and by 13 months was climbing those play tower ladders (and she was petite, about 20th percentile) and sometimes falling through the rungs and dangling by her hands, yelling, "help me!" I could hardly take my eyes off her when we were in the backyard, as she LOVED climbing that ladder. She's a talented equestrian now, at age 8.