Why as the current through a lamp and the voltage acros the lamp increases, theresistance increases?

Question

Why as the current through a lamp and the voltage acros the lamp increases, theresistance increases?

Answer 1

The voltage pushes electrons in the lamp filament to move faster, so they collide with each other more, and hinder the movement of each other more.  Resistance is the property of 'resisting the flow of charge' so if the electrons are bouncing about like stock cars, it follows that the available routes are blocked more often, which means less flow, more resistance.

Answer 2

It heats up and higher temperature means higher resistance.