portraits a question

From Wikipedia I found the following passage, "A form of art in photography is that of portrait photography. A portrait is the rendering of someone’s likeness. A portrait photographer not only wants to capture the true likeness, but also the personality of the individual. The photographer needs to be proficient not only in the workings and setting of the camera, but also needs to understand form and lighting. Great lighting and positioning can make someone appear at their best form if used correctly. Lighting and camera placement can also aid in correcting defects such as shortening a nose, making someone appear slimmer and other visual enhancements."
How far can one capture the personality of another in a photograph? How many students of photography have tried to think through this question? it is easy to contemplate this cynically and to dismiss this form of questioning as a waste of time. is it?