My twins are very different developmentally - one has always been faster with physical things while the other has been faster with cognitive things.
The latter seems very bright - he started copying me first (clapping etc), making consonant sounds, posting balls, stacking quite early. He's pulling up and cruising along the edges of things and is very stable, whereas his brother is trying to walk around and constantly falling down.
However, I've noticed recently that he's stopped doing things he used to do all the time. For example, he used to clap all the time - if I start singing "happy and you know it", he would start clapping after the first two words, and copying other things I did. He's stopped doing this completely.
Is this normal? Is it because he's focussed on learning to walk etc maybe? Just seems weird to learn things, do them all the time and then just stop!