A method identifies user demographic characteristics, such as age and gender. First, a plurality of photos are acquired from postings to a social media site by a specific user. A plurality of facial images are identified in the acquired photos. Using a selected subset of the facial images, the method estimates one or more demographic characteristics of the user. In some cases, the estimation uses a profile photograph of the user. In some cases, the facial images are clustered based on similarity. The cluster that most closely matches the profile photo is used for demographic analysis to estimate the characteristics of the user. In some cases, a cluster is selected based on cluster purity, and the images in the cluster are used to estimate the characteristics of the user. In some cases, other self-portrait features are used, such as large facial images or arms along the perimeter of photographs.