You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is This social milestone is established by age of ___________ and explain in detail?
Babies establish a smile on social contact by 2 months. Also done at 2 months Head sustained in a plane of the body on ventral suspension Follows moving object by 180 degrees Smiles on social contact Listen to voices and coos Ref : Nelson 20th edition pg no : 67