"Yes, you can harm a baby by picking him or her up too much...Research has clearly demonstrated that immediate-gratification training negatively impacts a child's ability to learn, affecting the skills of sitting, focusing, and concentrating." On Becoming Baby Wise by Gary Ezzo, M.A. and Robert Bucknam, M.D.
My sister did not follow Baby Wise with her 4 year old daughter yet I believe she is the smartest 4 year old that I have seen. She not only knows how to spell and write her name, rewrite sentences by looking at them but she communicates very effectively. The phrases she says makes you wonder where on earth did it come from. The grammatical structure of the sentences are 'adult-like'. She can hear a story or see something one time and yet she'll remember that months down the road and talk about it like it was yesterday. I don't believe that picking your child up all the time lessens their focus or concentration on items later on in life.
But what do you say?