Difference of standard deviations for 10,000 sample permutations-12-10-8-6-4-20246810120100200300400The red circle shows the difference σ(A) and σ(B) for the original samplesLower differences:5.8% of resamplesHigher differences:94.2% of resamples

The values are randomly shuffled between the two samples to see how much this changes the difference in their standard deviations.
An A-B difference further from zero than most shuffled cases suggests that A and B came from populations with different characteristics.