If I consider my own biases, I would consider a fit, well groomed person to be more competent. I believe this bias is based on fact that if someone is fit also means he/she is disciplined and well groomed is meticulous and these traits would transfer to other aspects of work also. Now, I understand that lot of things like age, genetics, ... make up for some of the signal that I am reading, but that is the nature of biases.