Not especially disagreeing with you personally here spratsmum, but your post got me thinking. Reading this made me try out my own fingernails on myself, and I have to say it would take a lot of effort to make those scratches, or more like gouges.
Any other ladies tried this? I've got mid-length strong natural sharpish nails (as opposed to thicker blunt acrylic nails) and there's no way I can scratch myself hard enough to cut the skin in an arm-extending, cat-scratch type movement. Even trying to dig my nails in hard and drag, it becomes too painful to continue long before any permanent mark is left on the skin.
Maybe I could practice on an apple or peach or something, but I think it would take quite sustained pressure and dragging to make those marks - eg clawing at someone's face while they're strangling you and won't let go (and their arms aren't free to block you). Also one of the scratches is a bit crooked, which would point to slower, sustained movement maybe?