Four simple smiley-like emoticons representing the four temperaments (choleric, melancholic, phlegmatic and sanguine), by the tilt of the eyes and the curve of the mouth. These two features seem to represent high/low energy, resp. positive/negative humours. I created the graphics file myself, but I do not know the source of this idea. As the four temperaments may not be represented absolutely convincingly by these four figures, their merit lies in their simplicity. If you can improve on these four figures without compromising their simplicity, please do so and replace my file!
Of this SVG, Roland Geider (Ogre); of the orignal,Noe