It is well known that biological motion conveys a wealth of socially meaningful information. From even a
brief exposure, biological motion cues enable the recognition of familiar people, and the inference of
attributes such as gender, age, mental state, actions and intentions. In this paper we show that from
the output of a video-based 3D human tracking algorithm we can infer physical attributes (e.g., gender
and weight) and aspects of mental state (e.g., happiness or sadness). In particular, with 3D articulated
tracking we avoid the need for view-based models, specific camera viewpoints, and constrained domains.
The task is useful for man–machine communication, and it provides a natural benchmark for evaluating
the performance of 3D pose tracking methods (vs. conventional Euclidean joint error metrics). We show
results on a large corpus of motion capture data and on the output of a simple 3D pose tracker applied to
videos of people walking.