From Nature:
Has anyone ever told you that you have the same expressions as your siblings or parents? You might think you picked that up by hanging around with your family too long. But scientists now say that such family ‘signatures’ may be genetic.
To separate the impact of mimicry from genetic inheritance, scientists at the University of Haifa, Israel, looked at people who were born blind.
The authors note that their blind subjects considered it to be a common public misconception that they can learn expressions by touch. The participants said that without a mental model of what a face looks like, it is hard to translate expressions felt through the hands to expressions on their own face.
Picture: expressions are similar between blind participants (left) and their relatives (right).
More here.