Density plot of effective temperature against R_var, showing the decrease in variability with increasing temperature for all the selected dwarf stars (top) and for those with Kepler magnitude  < 14 (bottom). This illustrates that the dearth of low variability starts at low temperatures is not a result of the increased noise floor of the cool, faint stars. The dashed line shows the solar variability level and the solid red line is twice the solar level.