There are three different stages of the sign language learning in babies, <em>¨Hands Babbling¨</em> is the first one, and arrives when the baby is between nine and eleven months old, before the first linguistic signs start, the baby already uses his hands as response to different environment events, the second stage and the moment when the baby starts to express himself, is the¨first signs¨ part, since the first year and on, the baby will start to show communication patterns with his hands.
And at the end, the <em>¨signed phrases¨</em> stage is when the baby starts to make their first signs combinations, expressing ideas and perceptions.
So based on the question, the age when Peyton will start to express his first signs will be since the first year of life (12 months), and on, the time starts from the 12 month, and start to develop in a different manner depending on the <em>¨learning curve¨ </em>of each individual.