I recommend checking out this Forbesarticle.

My biggest problem with headshots on your resumé is that your physical appearance really shouldn't influence your hiring at all. From a hiring perspective, the Forbes article says:

It’s illegal to consider factors like age, race, gender, religion, national origin, sexual orientation, or disability status in hiring decisions. So hiring authorities prefer to not “officially” know whether you’re a member of one of these protected classes. If you put a photo on your resume, you reveal some of these details. If the employer later interviews you but doesn’t hire you, it opens the possibility of a discrimination claim. Some companies will even flat-out reject resumes with photos, just to avoid that potential accusation.

This policy seems right on the money from a legal stand point, so I would argue including a photo actually hurts you.

Lastly, it's tacky.